From f6198d9abf453182f4b111e0579a7a4ef1614e79 Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Mon, 12 Aug 2013 17:50:37 -0400 Subject: - A large refactoring of the ``sqlalchemy.sql`` package has reorganized the import structure of many core modules. ``sqlalchemy.schema`` and ``sqlalchemy.types`` remain in the top-level package, but are now just lists of names that pull from within ``sqlalchemy.sql``. Their implementations are now broken out among ``sqlalchemy.sql.type_api``, ``sqlalchemy.sql.sqltypes``, ``sqlalchemy.sql.schema`` and ``sqlalchemy.sql.ddl``, the last of which was moved from ``sqlalchemy.engine``. ``sqlalchemy.sql.expression`` is also a namespace now which pulls implementations mostly from ``sqlalchemy.sql.elements``, ``sqlalchemy.sql.selectable``, and ``sqlalchemy.sql.dml``. Most of the "factory" functions used to create SQL expression objects have been moved to classmethods or constructors, which are exposed in ``sqlalchemy.sql.expression`` using a programmatic system. Care has been taken such that all the original import namespaces remain intact and there should be no impact on any existing applications. The rationale here was to break out these very large modules into smaller ones, provide more manageable lists of function names, to greatly reduce "import cycles" and clarify the up-front importing of names, and to remove the need for redundant functions and documentation throughout the expression package. --- lib/sqlalchemy/sql/schema.py | 3025 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 3025 insertions(+) create mode 100644 lib/sqlalchemy/sql/schema.py (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py new file mode 100644 index 000000000..dbd7ec03d --- /dev/null +++ b/lib/sqlalchemy/sql/schema.py @@ -0,0 +1,3025 @@ +# sqlalchemy/schema.py +# Copyright (C) 2005-2013 the SQLAlchemy authors and contributors +# +# This module is part of SQLAlchemy and is released under +# the MIT License: http://www.opensource.org/licenses/mit-license.php + +"""The schema module provides the building blocks for database metadata. + +Each element within this module describes a database entity which can be +created and dropped, or is otherwise part of such an entity. Examples include +tables, columns, sequences, and indexes. + +All entities are subclasses of :class:`~sqlalchemy.schema.SchemaItem`, and as +defined in this module they are intended to be agnostic of any vendor-specific +constructs. + +A collection of entities are grouped into a unit called +:class:`~sqlalchemy.schema.MetaData`. MetaData serves as a logical grouping of +schema elements, and can also be associated with an actual database connection +such that operations involving the contained elements can contact the database +as needed. + +Two of the elements here also build upon their "syntactic" counterparts, which +are defined in :class:`~sqlalchemy.sql.expression.`, specifically +:class:`~sqlalchemy.schema.Table` and :class:`~sqlalchemy.schema.Column`. +Since these objects are part of the SQL expression language, they are usable +as components in SQL expressions. + +""" + +import re +import inspect +from .. import exc, util, event, inspection +from ..events import SchemaEventTarget +from . import visitors +from . import type_api +from .base import _bind_or_error, ColumnCollection +from .elements import ClauseElement, ColumnClause, _truncated_label, \ + _as_truncated, TextClause, _literal_as_text,\ + ColumnElement, _find_columns +from .selectable import TableClause +import collections +import sqlalchemy +from . import ddl + +RETAIN_SCHEMA = util.symbol('retain_schema') + + +def _get_table_key(name, schema): + if schema is None: + return name + else: + return schema + "." + name + + +def _validate_dialect_kwargs(kwargs, name): + # validate remaining kwargs that they all specify DB prefixes + + for k in kwargs: + m = re.match('^(.+?)_.*', k) + if m is None: + raise TypeError("Additional arguments should be " + "named _, got '%s'" % k) + +@inspection._self_inspects +class SchemaItem(SchemaEventTarget, visitors.Visitable): + """Base class for items that define a database schema.""" + + __visit_name__ = 'schema_item' + quote = None + + def _init_items(self, *args): + """Initialize the list of child items for this SchemaItem.""" + + for item in args: + if item is not None: + item._set_parent_with_dispatch(self) + + def get_children(self, **kwargs): + """used to allow SchemaVisitor access""" + return [] + + def __repr__(self): + return util.generic_repr(self) + + @util.memoized_property + def info(self): + """Info dictionary associated with the object, allowing user-defined + data to be associated with this :class:`.SchemaItem`. + + The dictionary is automatically generated when first accessed. + It can also be specified in the constructor of some objects, + such as :class:`.Table` and :class:`.Column`. + + """ + return {} + + + +class Table(SchemaItem, TableClause): + """Represent a table in a database. + + e.g.:: + + mytable = Table("mytable", metadata, + Column('mytable_id', Integer, primary_key=True), + Column('value', String(50)) + ) + + The :class:`.Table` object constructs a unique instance of itself based + on its name and optional schema name within the given + :class:`.MetaData` object. Calling the :class:`.Table` + constructor with the same name and same :class:`.MetaData` argument + a second time will return the *same* :class:`.Table` object - in this way + the :class:`.Table` constructor acts as a registry function. + + See also: + + :ref:`metadata_describing` - Introduction to database metadata + + Constructor arguments are as follows: + + :param name: The name of this table as represented in the database. + + This property, along with the *schema*, indicates the *singleton + identity* of this table in relation to its parent :class:`.MetaData`. + Additional calls to :class:`.Table` with the same name, metadata, + and schema name will return the same :class:`.Table` object. + + Names which contain no upper case characters + will be treated as case insensitive names, and will not be quoted + unless they are a reserved word. Names with any number of upper + case characters will be quoted and sent exactly. Note that this + behavior applies even for databases which standardize upper + case names as case insensitive such as Oracle. + + :param metadata: a :class:`.MetaData` object which will contain this + table. The metadata is used as a point of association of this table + with other tables which are referenced via foreign key. It also + may be used to associate this table with a particular + :class:`.Connectable`. + + :param \*args: Additional positional arguments are used primarily + to add the list of :class:`.Column` objects contained within this + table. Similar to the style of a CREATE TABLE statement, other + :class:`.SchemaItem` constructs may be added here, including + :class:`.PrimaryKeyConstraint`, and :class:`.ForeignKeyConstraint`. + + :param autoload: Defaults to False: the Columns for this table should + be reflected from the database. Usually there will be no Column + objects in the constructor if this property is set. + + :param autoload_replace: If ``True``, when using ``autoload=True`` + and ``extend_existing=True``, + replace ``Column`` objects already present in the ``Table`` that's + in the ``MetaData`` registry with + what's reflected. Otherwise, all existing columns will be + excluded from the reflection process. Note that this does + not impact ``Column`` objects specified in the same call to ``Table`` + which includes ``autoload``, those always take precedence. + Defaults to ``True``. + + .. versionadded:: 0.7.5 + + :param autoload_with: If autoload==True, this is an optional Engine + or Connection instance to be used for the table reflection. If + ``None``, the underlying MetaData's bound connectable will be used. + + :param extend_existing: When ``True``, indicates that if this + :class:`.Table` is already present in the given :class:`.MetaData`, + apply further arguments within the constructor to the existing + :class:`.Table`. + + If ``extend_existing`` or ``keep_existing`` are not set, an error is + raised if additional table modifiers are specified when + the given :class:`.Table` is already present in the :class:`.MetaData`. + + .. versionchanged:: 0.7.4 + ``extend_existing`` will work in conjunction + with ``autoload=True`` to run a new reflection operation against + the database; new :class:`.Column` objects will be produced + from database metadata to replace those existing with the same + name, and additional :class:`.Column` objects not present + in the :class:`.Table` will be added. + + As is always the case with ``autoload=True``, :class:`.Column` + objects can be specified in the same :class:`.Table` constructor, + which will take precedence. I.e.:: + + Table("mytable", metadata, + Column('y', Integer), + extend_existing=True, + autoload=True, + autoload_with=engine + ) + + The above will overwrite all columns within ``mytable`` which + are present in the database, except for ``y`` which will be used as is + from the above definition. If the ``autoload_replace`` flag + is set to False, no existing columns will be replaced. + + :param implicit_returning: True by default - indicates that + RETURNING can be used by default to fetch newly inserted primary key + values, for backends which support this. Note that + create_engine() also provides an implicit_returning flag. + + :param include_columns: A list of strings indicating a subset of + columns to be loaded via the ``autoload`` operation; table columns who + aren't present in this list will not be represented on the resulting + ``Table`` object. Defaults to ``None`` which indicates all columns + should be reflected. + + :param info: Optional data dictionary which will be populated into the + :attr:`.SchemaItem.info` attribute of this object. + + :param keep_existing: When ``True``, indicates that if this Table + is already present in the given :class:`.MetaData`, ignore + further arguments within the constructor to the existing + :class:`.Table`, and return the :class:`.Table` object as + originally created. This is to allow a function that wishes + to define a new :class:`.Table` on first call, but on + subsequent calls will return the same :class:`.Table`, + without any of the declarations (particularly constraints) + being applied a second time. Also see extend_existing. + + If extend_existing or keep_existing are not set, an error is + raised if additional table modifiers are specified when + the given :class:`.Table` is already present in the :class:`.MetaData`. + + :param listeners: A list of tuples of the form ``(, )`` + which will be passed to :func:`.event.listen` upon construction. + This alternate hook to :func:`.event.listen` allows the establishment + of a listener function specific to this :class:`.Table` before + the "autoload" process begins. Particularly useful for + the :meth:`.DDLEvents.column_reflect` event:: + + def listen_for_reflect(table, column_info): + "handle the column reflection event" + # ... + + t = Table( + 'sometable', + autoload=True, + listeners=[ + ('column_reflect', listen_for_reflect) + ]) + + :param mustexist: When ``True``, indicates that this Table must already + be present in the given :class:`.MetaData` collection, else + an exception is raised. + + :param prefixes: + A list of strings to insert after CREATE in the CREATE TABLE + statement. They will be separated by spaces. + + :param quote: Force quoting of this table's name on or off, corresponding + to ``True`` or ``False``. When left at its default of ``None``, + the column identifier will be quoted according to whether the name is + case sensitive (identifiers with at least one upper case character are + treated as case sensitive), or if it's a reserved word. This flag + is only needed to force quoting of a reserved word which is not known + by the SQLAlchemy dialect. + + :param quote_schema: same as 'quote' but applies to the schema identifier. + + :param schema: The *schema name* for this table, which is required if + the table resides in a schema other than the default selected schema + for the engine's database connection. Defaults to ``None``. + + :param useexisting: Deprecated. Use extend_existing. + + """ + + __visit_name__ = 'table' + + def __new__(cls, *args, **kw): + if not args: + # python3k pickle seems to call this + return object.__new__(cls) + + try: + name, metadata, args = args[0], args[1], args[2:] + except IndexError: + raise TypeError("Table() takes at least two arguments") + + schema = kw.get('schema', None) + if schema is None: + schema = metadata.schema + keep_existing = kw.pop('keep_existing', False) + extend_existing = kw.pop('extend_existing', False) + if 'useexisting' in kw: + msg = "useexisting is deprecated. Use extend_existing." + util.warn_deprecated(msg) + if extend_existing: + msg = "useexisting is synonymous with extend_existing." + raise exc.ArgumentError(msg) + extend_existing = kw.pop('useexisting', False) + + if keep_existing and extend_existing: + msg = "keep_existing and extend_existing are mutually exclusive." + raise exc.ArgumentError(msg) + + mustexist = kw.pop('mustexist', False) + key = _get_table_key(name, schema) + if key in metadata.tables: + if not keep_existing and not extend_existing and bool(args): + raise exc.InvalidRequestError( + "Table '%s' is already defined for this MetaData " + "instance. Specify 'extend_existing=True' " + "to redefine " + "options and columns on an " + "existing Table object." % key) + table = metadata.tables[key] + if extend_existing: + table._init_existing(*args, **kw) + return table + else: + if mustexist: + raise exc.InvalidRequestError( + "Table '%s' not defined" % (key)) + table = object.__new__(cls) + table.dispatch.before_parent_attach(table, metadata) + metadata._add_table(name, schema, table) + try: + table._init(name, metadata, *args, **kw) + table.dispatch.after_parent_attach(table, metadata) + return table + except: + #metadata._remove_table(name, schema) + raise + + def __init__(self, *args, **kw): + """Constructor for :class:`~.schema.Table`. + + This method is a no-op. See the top-level + documentation for :class:`~.schema.Table` + for constructor arguments. + + """ + # __init__ is overridden to prevent __new__ from + # calling the superclass constructor. + + def _init(self, name, metadata, *args, **kwargs): + super(Table, self).__init__(name) + self.metadata = metadata + self.schema = kwargs.pop('schema', None) + if self.schema is None: + self.schema = metadata.schema + self.quote_schema = kwargs.pop( + 'quote_schema', metadata.quote_schema) + else: + self.quote_schema = kwargs.pop('quote_schema', None) + + self.indexes = set() + self.constraints = set() + self._columns = ColumnCollection() + PrimaryKeyConstraint()._set_parent_with_dispatch(self) + self.foreign_keys = set() + self._extra_dependencies = set() + self.kwargs = {} + if self.schema is not None: + self.fullname = "%s.%s" % (self.schema, self.name) + else: + self.fullname = self.name + + autoload = kwargs.pop('autoload', False) + autoload_with = kwargs.pop('autoload_with', None) + # this argument is only used with _init_existing() + kwargs.pop('autoload_replace', True) + include_columns = kwargs.pop('include_columns', None) + + self.implicit_returning = kwargs.pop('implicit_returning', True) + self.quote = kwargs.pop('quote', None) + if 'info' in kwargs: + self.info = kwargs.pop('info') + if 'listeners' in kwargs: + listeners = kwargs.pop('listeners') + for evt, fn in listeners: + event.listen(self, evt, fn) + + self._prefixes = kwargs.pop('prefixes', []) + + self._extra_kwargs(**kwargs) + + # load column definitions from the database if 'autoload' is defined + # we do it after the table is in the singleton dictionary to support + # circular foreign keys + if autoload: + self._autoload(metadata, autoload_with, include_columns) + + # initialize all the column, etc. objects. done after reflection to + # allow user-overrides + self._init_items(*args) + + def _autoload(self, metadata, autoload_with, include_columns, + exclude_columns=()): + if self.primary_key.columns: + PrimaryKeyConstraint(*[ + c for c in self.primary_key.columns + if c.key in exclude_columns + ])._set_parent_with_dispatch(self) + + if autoload_with: + autoload_with.run_callable( + autoload_with.dialect.reflecttable, + self, include_columns, exclude_columns + ) + else: + bind = _bind_or_error(metadata, + msg="No engine is bound to this Table's MetaData. " + "Pass an engine to the Table via " + "autoload_with=, " + "or associate the MetaData with an engine via " + "metadata.bind=") + bind.run_callable( + bind.dialect.reflecttable, + self, include_columns, exclude_columns + ) + + @property + def _sorted_constraints(self): + """Return the set of constraints as a list, sorted by creation + order. + + """ + return sorted(self.constraints, key=lambda c: c._creation_order) + + def _init_existing(self, *args, **kwargs): + autoload = kwargs.pop('autoload', False) + autoload_with = kwargs.pop('autoload_with', None) + autoload_replace = kwargs.pop('autoload_replace', True) + schema = kwargs.pop('schema', None) + if schema and schema != self.schema: + raise exc.ArgumentError( + "Can't change schema of existing table from '%s' to '%s'", + (self.schema, schema)) + + include_columns = kwargs.pop('include_columns', None) + + if include_columns is not None: + for c in self.c: + if c.name not in include_columns: + self._columns.remove(c) + + for key in ('quote', 'quote_schema'): + if key in kwargs: + setattr(self, key, kwargs.pop(key)) + + if 'info' in kwargs: + self.info = kwargs.pop('info') + + if autoload: + if not autoload_replace: + exclude_columns = [c.name for c in self.c] + else: + exclude_columns = () + self._autoload( + self.metadata, autoload_with, include_columns, exclude_columns) + + self._extra_kwargs(**kwargs) + self._init_items(*args) + + def _extra_kwargs(self, **kwargs): + # validate remaining kwargs that they all specify DB prefixes + _validate_dialect_kwargs(kwargs, "Table") + self.kwargs.update(kwargs) + + def _init_collections(self): + pass + + @util.memoized_property + def _autoincrement_column(self): + for col in self.primary_key: + if col.autoincrement and \ + col.type._type_affinity is not None and \ + issubclass(col.type._type_affinity, type_api.INTEGERTYPE._type_affinity) and \ + (not col.foreign_keys or col.autoincrement == 'ignore_fk') and \ + isinstance(col.default, (type(None), Sequence)) and \ + (col.server_default is None or col.server_default.reflected): + return col + + @property + def key(self): + return _get_table_key(self.name, self.schema) + + def __repr__(self): + return "Table(%s)" % ', '.join( + [repr(self.name)] + [repr(self.metadata)] + + [repr(x) for x in self.columns] + + ["%s=%s" % (k, repr(getattr(self, k))) for k in ['schema']]) + + def __str__(self): + return _get_table_key(self.description, self.schema) + + @property + def bind(self): + """Return the connectable associated with this Table.""" + + return self.metadata and self.metadata.bind or None + + def add_is_dependent_on(self, table): + """Add a 'dependency' for this Table. + + This is another Table object which must be created + first before this one can, or dropped after this one. + + Usually, dependencies between tables are determined via + ForeignKey objects. However, for other situations that + create dependencies outside of foreign keys (rules, inheriting), + this method can manually establish such a link. + + """ + self._extra_dependencies.add(table) + + def append_column(self, column): + """Append a :class:`~.schema.Column` to this :class:`~.schema.Table`. + + The "key" of the newly added :class:`~.schema.Column`, i.e. the + value of its ``.key`` attribute, will then be available + in the ``.c`` collection of this :class:`~.schema.Table`, and the + column definition will be included in any CREATE TABLE, SELECT, + UPDATE, etc. statements generated from this :class:`~.schema.Table` + construct. + + Note that this does **not** change the definition of the table + as it exists within any underlying database, assuming that + table has already been created in the database. Relational + databases support the addition of columns to existing tables + using the SQL ALTER command, which would need to be + emitted for an already-existing table that doesn't contain + the newly added column. + + """ + + column._set_parent_with_dispatch(self) + + def append_constraint(self, constraint): + """Append a :class:`~.schema.Constraint` to this + :class:`~.schema.Table`. + + This has the effect of the constraint being included in any + future CREATE TABLE statement, assuming specific DDL creation + events have not been associated with the given + :class:`~.schema.Constraint` object. + + Note that this does **not** produce the constraint within the + relational database automatically, for a table that already exists + in the database. To add a constraint to an + existing relational database table, the SQL ALTER command must + be used. SQLAlchemy also provides the + :class:`.AddConstraint` construct which can produce this SQL when + invoked as an executable clause. + + """ + + constraint._set_parent_with_dispatch(self) + + def append_ddl_listener(self, event_name, listener): + """Append a DDL event listener to this ``Table``. + + .. deprecated:: 0.7 + See :class:`.DDLEvents`. + + """ + + def adapt_listener(target, connection, **kw): + listener(event_name, target, connection) + + event.listen(self, "" + event_name.replace('-', '_'), adapt_listener) + + def _set_parent(self, metadata): + metadata._add_table(self.name, self.schema, self) + self.metadata = metadata + + def get_children(self, column_collections=True, + schema_visitor=False, **kw): + if not schema_visitor: + return TableClause.get_children( + self, column_collections=column_collections, **kw) + else: + if column_collections: + return list(self.columns) + else: + return [] + + def exists(self, bind=None): + """Return True if this table exists.""" + + if bind is None: + bind = _bind_or_error(self) + + return bind.run_callable(bind.dialect.has_table, + self.name, schema=self.schema) + + def create(self, bind=None, checkfirst=False): + """Issue a ``CREATE`` statement for this + :class:`.Table`, using the given :class:`.Connectable` + for connectivity. + + See also :meth:`.MetaData.create_all`. + + """ + + if bind is None: + bind = _bind_or_error(self) + bind._run_visitor(ddl.SchemaGenerator, + self, + checkfirst=checkfirst) + + def drop(self, bind=None, checkfirst=False): + """Issue a ``DROP`` statement for this + :class:`.Table`, using the given :class:`.Connectable` + for connectivity. + + See also :meth:`.MetaData.drop_all`. + + """ + if bind is None: + bind = _bind_or_error(self) + bind._run_visitor(ddl.SchemaDropper, + self, + checkfirst=checkfirst) + + def tometadata(self, metadata, schema=RETAIN_SCHEMA): + """Return a copy of this :class:`.Table` associated with a different + :class:`.MetaData`. + + E.g.:: + + some_engine = create_engine("sqlite:///some.db") + + # create two metadata + meta1 = MetaData() + meta2 = MetaData() + + # load 'users' from the sqlite engine + users_table = Table('users', meta1, autoload=True, + autoload_with=some_engine) + + # create the same Table object for the plain metadata + users_table_2 = users_table.tometadata(meta2) + + :param metadata: Target :class:`.MetaData` object. + :param schema: Optional string name of a target schema, or + ``None`` for no schema. The :class:`.Table` object will be + given this schema name upon copy. Defaults to the special + symbol :attr:`.RETAIN_SCHEMA` which indicates no change should be + made to the schema name of the resulting :class:`.Table`. + + """ + + if schema is RETAIN_SCHEMA: + schema = self.schema + elif schema is None: + schema = metadata.schema + key = _get_table_key(self.name, schema) + if key in metadata.tables: + util.warn("Table '%s' already exists within the given " + "MetaData - not copying." % self.description) + return metadata.tables[key] + + args = [] + for c in self.columns: + args.append(c.copy(schema=schema)) + table = Table( + self.name, metadata, schema=schema, + *args, **self.kwargs + ) + for c in self.constraints: + table.append_constraint(c.copy(schema=schema, target_table=table)) + + for index in self.indexes: + # skip indexes that would be generated + # by the 'index' flag on Column + if len(index.columns) == 1 and \ + list(index.columns)[0].index: + continue + Index(index.name, + unique=index.unique, + *[table.c[col] for col in index.columns.keys()], + **index.kwargs) + table.dispatch._update(self.dispatch) + return table + + +class Column(SchemaItem, ColumnClause): + """Represents a column in a database table.""" + + __visit_name__ = 'column' + + def __init__(self, *args, **kwargs): + """ + Construct a new ``Column`` object. + + :param name: The name of this column as represented in the database. + This argument may be the first positional argument, or specified + via keyword. + + Names which contain no upper case characters + will be treated as case insensitive names, and will not be quoted + unless they are a reserved word. Names with any number of upper + case characters will be quoted and sent exactly. Note that this + behavior applies even for databases which standardize upper + case names as case insensitive such as Oracle. + + The name field may be omitted at construction time and applied + later, at any time before the Column is associated with a + :class:`.Table`. This is to support convenient + usage within the :mod:`~sqlalchemy.ext.declarative` extension. + + :param type\_: The column's type, indicated using an instance which + subclasses :class:`~sqlalchemy.types.TypeEngine`. If no arguments + are required for the type, the class of the type can be sent + as well, e.g.:: + + # use a type with arguments + Column('data', String(50)) + + # use no arguments + Column('level', Integer) + + The ``type`` argument may be the second positional argument + or specified by keyword. + + If the ``type`` is ``None`` or is omitted, it will first default to the special + type :class:`.NullType`. If and when this :class:`.Column` is + made to refer to another column using :class:`.ForeignKey` + and/or :class:`.ForeignKeyConstraint`, the type of the remote-referenced + column will be copied to this column as well, at the moment that + the foreign key is resolved against that remote :class:`.Column` + object. + + .. versionchanged:: 0.9.0 + Support for propagation of type to a :class:`.Column` from its + :class:`.ForeignKey` object has been improved and should be + more reliable and timely. + + :param \*args: Additional positional arguments include various + :class:`.SchemaItem` derived constructs which will be applied + as options to the column. These include instances of + :class:`.Constraint`, :class:`.ForeignKey`, :class:`.ColumnDefault`, + and :class:`.Sequence`. In some cases an equivalent keyword + argument is available such as ``server_default``, ``default`` + and ``unique``. + + :param autoincrement: This flag may be set to ``False`` to + indicate an integer primary key column that should not be + considered to be the "autoincrement" column, that is + the integer primary key column which generates values + implicitly upon INSERT and whose value is usually returned + via the DBAPI cursor.lastrowid attribute. It defaults + to ``True`` to satisfy the common use case of a table + with a single integer primary key column. If the table + has a composite primary key consisting of more than one + integer column, set this flag to True only on the + column that should be considered "autoincrement". + + The setting *only* has an effect for columns which are: + + * Integer derived (i.e. INT, SMALLINT, BIGINT). + + * Part of the primary key + + * Are not referenced by any foreign keys, unless + the value is specified as ``'ignore_fk'`` + + .. versionadded:: 0.7.4 + + * have no server side or client side defaults (with the exception + of Postgresql SERIAL). + + The setting has these two effects on columns that meet the + above criteria: + + * DDL issued for the column will include database-specific + keywords intended to signify this column as an + "autoincrement" column, such as AUTO INCREMENT on MySQL, + SERIAL on Postgresql, and IDENTITY on MS-SQL. It does + *not* issue AUTOINCREMENT for SQLite since this is a + special SQLite flag that is not required for autoincrementing + behavior. See the SQLite dialect documentation for + information on SQLite's AUTOINCREMENT. + + * The column will be considered to be available as + cursor.lastrowid or equivalent, for those dialects which + "post fetch" newly inserted identifiers after a row has + been inserted (SQLite, MySQL, MS-SQL). It does not have + any effect in this regard for databases that use sequences + to generate primary key identifiers (i.e. Firebird, Postgresql, + Oracle). + + .. versionchanged:: 0.7.4 + ``autoincrement`` accepts a special value ``'ignore_fk'`` + to indicate that autoincrementing status regardless of foreign + key references. This applies to certain composite foreign key + setups, such as the one demonstrated in the ORM documentation + at :ref:`post_update`. + + :param default: A scalar, Python callable, or + :class:`.ColumnElement` expression representing the + *default value* for this column, which will be invoked upon insert + if this column is otherwise not specified in the VALUES clause of + the insert. This is a shortcut to using :class:`.ColumnDefault` as + a positional argument; see that class for full detail on the + structure of the argument. + + Contrast this argument to ``server_default`` which creates a + default generator on the database side. + + :param doc: optional String that can be used by the ORM or similar + to document attributes. This attribute does not render SQL + comments (a future attribute 'comment' will achieve that). + + :param key: An optional string identifier which will identify this + ``Column`` object on the :class:`.Table`. When a key is provided, + this is the only identifier referencing the ``Column`` within the + application, including ORM attribute mapping; the ``name`` field + is used only when rendering SQL. + + :param index: When ``True``, indicates that the column is indexed. + This is a shortcut for using a :class:`.Index` construct on the + table. To specify indexes with explicit names or indexes that + contain multiple columns, use the :class:`.Index` construct + instead. + + :param info: Optional data dictionary which will be populated into the + :attr:`.SchemaItem.info` attribute of this object. + + :param nullable: If set to the default of ``True``, indicates the + column will be rendered as allowing NULL, else it's rendered as + NOT NULL. This parameter is only used when issuing CREATE TABLE + statements. + + :param onupdate: A scalar, Python callable, or + :class:`~sqlalchemy.sql.expression.ClauseElement` representing a + default value to be applied to the column within UPDATE + statements, which wil be invoked upon update if this column is not + present in the SET clause of the update. This is a shortcut to + using :class:`.ColumnDefault` as a positional argument with + ``for_update=True``. + + :param primary_key: If ``True``, marks this column as a primary key + column. Multiple columns can have this flag set to specify + composite primary keys. As an alternative, the primary key of a + :class:`.Table` can be specified via an explicit + :class:`.PrimaryKeyConstraint` object. + + :param server_default: A :class:`.FetchedValue` instance, str, Unicode + or :func:`~sqlalchemy.sql.expression.text` construct representing + the DDL DEFAULT value for the column. + + String types will be emitted as-is, surrounded by single quotes:: + + Column('x', Text, server_default="val") + + x TEXT DEFAULT 'val' + + A :func:`~sqlalchemy.sql.expression.text` expression will be + rendered as-is, without quotes:: + + Column('y', DateTime, server_default=text('NOW()'))0 + + y DATETIME DEFAULT NOW() + + Strings and text() will be converted into a :class:`.DefaultClause` + object upon initialization. + + Use :class:`.FetchedValue` to indicate that an already-existing + column will generate a default value on the database side which + will be available to SQLAlchemy for post-fetch after inserts. This + construct does not specify any DDL and the implementation is left + to the database, such as via a trigger. + + :param server_onupdate: A :class:`.FetchedValue` instance + representing a database-side default generation function. This + indicates to SQLAlchemy that a newly generated value will be + available after updates. This construct does not specify any DDL + and the implementation is left to the database, such as via a + trigger. + + :param quote: Force quoting of this column's name on or off, + corresponding to ``True`` or ``False``. When left at its default + of ``None``, the column identifier will be quoted according to + whether the name is case sensitive (identifiers with at least one + upper case character are treated as case sensitive), or if it's a + reserved word. This flag is only needed to force quoting of a + reserved word which is not known by the SQLAlchemy dialect. + + :param unique: When ``True``, indicates that this column contains a + unique constraint, or if ``index`` is ``True`` as well, indicates + that the :class:`.Index` should be created with the unique flag. + To specify multiple columns in the constraint/index or to specify + an explicit name, use the :class:`.UniqueConstraint` or + :class:`.Index` constructs explicitly. + + """ + + name = kwargs.pop('name', None) + type_ = kwargs.pop('type_', None) + args = list(args) + if args: + if isinstance(args[0], util.string_types): + if name is not None: + raise exc.ArgumentError( + "May not pass name positionally and as a keyword.") + name = args.pop(0) + if args: + coltype = args[0] + + if hasattr(coltype, "_sqla_type"): + if type_ is not None: + raise exc.ArgumentError( + "May not pass type_ positionally and as a keyword.") + type_ = args.pop(0) + + super(Column, self).__init__(name, type_) + self.key = kwargs.pop('key', name) + self.primary_key = kwargs.pop('primary_key', False) + self.nullable = kwargs.pop('nullable', not self.primary_key) + self.default = kwargs.pop('default', None) + self.server_default = kwargs.pop('server_default', None) + self.server_onupdate = kwargs.pop('server_onupdate', None) + self.index = kwargs.pop('index', None) + self.unique = kwargs.pop('unique', None) + self.quote = kwargs.pop('quote', None) + self.doc = kwargs.pop('doc', None) + self.onupdate = kwargs.pop('onupdate', None) + self.autoincrement = kwargs.pop('autoincrement', True) + self.constraints = set() + self.foreign_keys = set() + + # check if this Column is proxying another column + if '_proxies' in kwargs: + self._proxies = kwargs.pop('_proxies') + # otherwise, add DDL-related events + elif isinstance(self.type, SchemaEventTarget): + self.type._set_parent_with_dispatch(self) + + if self.default is not None: + if isinstance(self.default, (ColumnDefault, Sequence)): + args.append(self.default) + else: + if getattr(self.type, '_warn_on_bytestring', False): + if isinstance(self.default, util.binary_type): + util.warn("Unicode column received non-unicode " + "default value.") + args.append(ColumnDefault(self.default)) + + if self.server_default is not None: + if isinstance(self.server_default, FetchedValue): + args.append(self.server_default._as_for_update(False)) + else: + args.append(DefaultClause(self.server_default)) + + if self.onupdate is not None: + if isinstance(self.onupdate, (ColumnDefault, Sequence)): + args.append(self.onupdate) + else: + args.append(ColumnDefault(self.onupdate, for_update=True)) + + if self.server_onupdate is not None: + if isinstance(self.server_onupdate, FetchedValue): + args.append(self.server_onupdate._as_for_update(True)) + else: + args.append(DefaultClause(self.server_onupdate, + for_update=True)) + self._init_items(*args) + + util.set_creation_order(self) + + if 'info' in kwargs: + self.info = kwargs.pop('info') + + if kwargs: + raise exc.ArgumentError( + "Unknown arguments passed to Column: " + repr(list(kwargs))) + + def __str__(self): + if self.name is None: + return "(no name)" + elif self.table is not None: + if self.table.named_with_column: + return (self.table.description + "." + self.description) + else: + return self.description + else: + return self.description + + def references(self, column): + """Return True if this Column references the given column via foreign + key.""" + + for fk in self.foreign_keys: + if fk.column.proxy_set.intersection(column.proxy_set): + return True + else: + return False + + def append_foreign_key(self, fk): + fk._set_parent_with_dispatch(self) + + def __repr__(self): + kwarg = [] + if self.key != self.name: + kwarg.append('key') + if self.primary_key: + kwarg.append('primary_key') + if not self.nullable: + kwarg.append('nullable') + if self.onupdate: + kwarg.append('onupdate') + if self.default: + kwarg.append('default') + if self.server_default: + kwarg.append('server_default') + return "Column(%s)" % ', '.join( + [repr(self.name)] + [repr(self.type)] + + [repr(x) for x in self.foreign_keys if x is not None] + + [repr(x) for x in self.constraints] + + [(self.table is not None and "table=<%s>" % + self.table.description or "table=None")] + + ["%s=%s" % (k, repr(getattr(self, k))) for k in kwarg]) + + def _set_parent(self, table): + if not self.name: + raise exc.ArgumentError( + "Column must be constructed with a non-blank name or " + "assign a non-blank .name before adding to a Table.") + if self.key is None: + self.key = self.name + + existing = getattr(self, 'table', None) + if existing is not None and existing is not table: + raise exc.ArgumentError( + "Column object already assigned to Table '%s'" % + existing.description) + + if self.key in table._columns: + col = table._columns.get(self.key) + if col is not self: + for fk in col.foreign_keys: + table.foreign_keys.remove(fk) + if fk.constraint in table.constraints: + # this might have been removed + # already, if it's a composite constraint + # and more than one col being replaced + table.constraints.remove(fk.constraint) + + table._columns.replace(self) + + if self.primary_key: + table.primary_key._replace(self) + Table._autoincrement_column._reset(table) + elif self.key in table.primary_key: + raise exc.ArgumentError( + "Trying to redefine primary-key column '%s' as a " + "non-primary-key column on table '%s'" % ( + self.key, table.fullname)) + self.table = table + + if self.index: + if isinstance(self.index, util.string_types): + raise exc.ArgumentError( + "The 'index' keyword argument on Column is boolean only. " + "To create indexes with a specific name, create an " + "explicit Index object external to the Table.") + Index(_truncated_label('ix_%s' % self._label), + self, unique=self.unique) + elif self.unique: + if isinstance(self.unique, util.string_types): + raise exc.ArgumentError( + "The 'unique' keyword argument on Column is boolean " + "only. To create unique constraints or indexes with a " + "specific name, append an explicit UniqueConstraint to " + "the Table's list of elements, or create an explicit " + "Index object external to the Table.") + table.append_constraint(UniqueConstraint(self.key)) + + fk_key = (table.key, self.key) + if fk_key in self.table.metadata._fk_memos: + for fk in self.table.metadata._fk_memos[fk_key]: + fk._set_remote_table(table) + + def _on_table_attach(self, fn): + if self.table is not None: + fn(self, self.table) + event.listen(self, 'after_parent_attach', fn) + + def copy(self, **kw): + """Create a copy of this ``Column``, unitialized. + + This is used in ``Table.tometadata``. + + """ + + # Constraint objects plus non-constraint-bound ForeignKey objects + args = \ + [c.copy(**kw) for c in self.constraints] + \ + [c.copy(**kw) for c in self.foreign_keys if not c.constraint] + + type_ = self.type + if isinstance(type_, SchemaEventTarget): + type_ = type_.copy(**kw) + + c = self._constructor( + name=self.name, + type_=type_, + key=self.key, + primary_key=self.primary_key, + nullable=self.nullable, + unique=self.unique, + quote=self.quote, + index=self.index, + autoincrement=self.autoincrement, + default=self.default, + server_default=self.server_default, + onupdate=self.onupdate, + server_onupdate=self.server_onupdate, + info=self.info, + doc=self.doc, + *args + ) + c.dispatch._update(self.dispatch) + return c + + def _make_proxy(self, selectable, name=None, key=None, + name_is_truncatable=False, **kw): + """Create a *proxy* for this column. + + This is a copy of this ``Column`` referenced by a different parent + (such as an alias or select statement). The column should + be used only in select scenarios, as its full DDL/default + information is not transferred. + + """ + fk = [ForeignKey(f.column, _constraint=f.constraint) + for f in self.foreign_keys] + if name is None and self.name is None: + raise exc.InvalidRequestError("Cannot initialize a sub-selectable" + " with this Column object until it's 'name' has " + "been assigned.") + try: + c = self._constructor( + _as_truncated(name or self.name) if \ + name_is_truncatable else (name or self.name), + self.type, + key=key if key else name if name else self.key, + primary_key=self.primary_key, + nullable=self.nullable, + quote=self.quote, + _proxies=[self], *fk) + except TypeError: + util.raise_from_cause( + TypeError( + "Could not create a copy of this %r object. " + "Ensure the class includes a _constructor() " + "attribute or method which accepts the " + "standard Column constructor arguments, or " + "references the Column class itself." % self.__class__) + ) + + c.table = selectable + selectable._columns.add(c) + if selectable._is_clone_of is not None: + c._is_clone_of = selectable._is_clone_of.columns[c.key] + if self.primary_key: + selectable.primary_key.add(c) + c.dispatch.after_parent_attach(c, selectable) + return c + + def get_children(self, schema_visitor=False, **kwargs): + if schema_visitor: + return [x for x in (self.default, self.onupdate) + if x is not None] + \ + list(self.foreign_keys) + list(self.constraints) + else: + return ColumnClause.get_children(self, **kwargs) + + +class ForeignKey(SchemaItem): + """Defines a dependency between two columns. + + ``ForeignKey`` is specified as an argument to a :class:`.Column` object, + e.g.:: + + t = Table("remote_table", metadata, + Column("remote_id", ForeignKey("main_table.id")) + ) + + Note that ``ForeignKey`` is only a marker object that defines + a dependency between two columns. The actual constraint + is in all cases represented by the :class:`.ForeignKeyConstraint` + object. This object will be generated automatically when + a ``ForeignKey`` is associated with a :class:`.Column` which + in turn is associated with a :class:`.Table`. Conversely, + when :class:`.ForeignKeyConstraint` is applied to a :class:`.Table`, + ``ForeignKey`` markers are automatically generated to be + present on each associated :class:`.Column`, which are also + associated with the constraint object. + + Note that you cannot define a "composite" foreign key constraint, + that is a constraint between a grouping of multiple parent/child + columns, using ``ForeignKey`` objects. To define this grouping, + the :class:`.ForeignKeyConstraint` object must be used, and applied + to the :class:`.Table`. The associated ``ForeignKey`` objects + are created automatically. + + The ``ForeignKey`` objects associated with an individual + :class:`.Column` object are available in the `foreign_keys` collection + of that column. + + Further examples of foreign key configuration are in + :ref:`metadata_foreignkeys`. + + """ + + __visit_name__ = 'foreign_key' + + def __init__(self, column, _constraint=None, use_alter=False, name=None, + onupdate=None, ondelete=None, deferrable=None, + schema=None, + initially=None, link_to_name=False, match=None): + """ + Construct a column-level FOREIGN KEY. + + The :class:`.ForeignKey` object when constructed generates a + :class:`.ForeignKeyConstraint` which is associated with the parent + :class:`.Table` object's collection of constraints. + + :param column: A single target column for the key relationship. A + :class:`.Column` object or a column name as a string: + ``tablename.columnkey`` or ``schema.tablename.columnkey``. + ``columnkey`` is the ``key`` which has been assigned to the column + (defaults to the column name itself), unless ``link_to_name`` is + ``True`` in which case the rendered name of the column is used. + + .. versionadded:: 0.7.4 + Note that if the schema name is not included, and the + underlying :class:`.MetaData` has a "schema", that value will + be used. + + :param name: Optional string. An in-database name for the key if + `constraint` is not provided. + + :param onupdate: Optional string. If set, emit ON UPDATE when + issuing DDL for this constraint. Typical values include CASCADE, + DELETE and RESTRICT. + + :param ondelete: Optional string. If set, emit ON DELETE when + issuing DDL for this constraint. Typical values include CASCADE, + DELETE and RESTRICT. + + :param deferrable: Optional bool. If set, emit DEFERRABLE or NOT + DEFERRABLE when issuing DDL for this constraint. + + :param initially: Optional string. If set, emit INITIALLY when + issuing DDL for this constraint. + + :param link_to_name: if True, the string name given in ``column`` is + the rendered name of the referenced column, not its locally + assigned ``key``. + + :param use_alter: passed to the underlying + :class:`.ForeignKeyConstraint` to indicate the constraint should be + generated/dropped externally from the CREATE TABLE/ DROP TABLE + statement. See that classes' constructor for details. + + :param match: Optional string. If set, emit MATCH when issuing + DDL for this constraint. Typical values include SIMPLE, PARTIAL + and FULL. + + """ + + self._colspec = column + + # the linked ForeignKeyConstraint. + # ForeignKey will create this when parent Column + # is attached to a Table, *or* ForeignKeyConstraint + # object passes itself in when creating ForeignKey + # markers. + self.constraint = _constraint + self.parent = None + self.use_alter = use_alter + self.name = name + self.onupdate = onupdate + self.ondelete = ondelete + self.deferrable = deferrable + self.initially = initially + self.link_to_name = link_to_name + self.match = match + + def __repr__(self): + return "ForeignKey(%r)" % self._get_colspec() + + def copy(self, schema=None): + """Produce a copy of this :class:`.ForeignKey` object. + + The new :class:`.ForeignKey` will not be bound + to any :class:`.Column`. + + This method is usually used by the internal + copy procedures of :class:`.Column`, :class:`.Table`, + and :class:`.MetaData`. + + :param schema: The returned :class:`.ForeignKey` will + reference the original table and column name, qualified + by the given string schema name. + + """ + + fk = ForeignKey( + self._get_colspec(schema=schema), + use_alter=self.use_alter, + name=self.name, + onupdate=self.onupdate, + ondelete=self.ondelete, + deferrable=self.deferrable, + initially=self.initially, + link_to_name=self.link_to_name, + match=self.match + ) + fk.dispatch._update(self.dispatch) + return fk + + def _get_colspec(self, schema=None): + """Return a string based 'column specification' for this + :class:`.ForeignKey`. + + This is usually the equivalent of the string-based "tablename.colname" + argument first passed to the object's constructor. + + """ + if schema: + return schema + "." + self.column.table.name + \ + "." + self.column.key + elif isinstance(self._colspec, util.string_types): + return self._colspec + elif hasattr(self._colspec, '__clause_element__'): + _column = self._colspec.__clause_element__() + else: + _column = self._colspec + + return "%s.%s" % (_column.table.fullname, _column.key) + + + target_fullname = property(_get_colspec) + + def references(self, table): + """Return True if the given :class:`.Table` is referenced by this + :class:`.ForeignKey`.""" + + return table.corresponding_column(self.column) is not None + + def get_referent(self, table): + """Return the :class:`.Column` in the given :class:`.Table` + referenced by this :class:`.ForeignKey`. + + Returns None if this :class:`.ForeignKey` does not reference the given + :class:`.Table`. + + """ + + return table.corresponding_column(self.column) + + @util.memoized_property + def _column_tokens(self): + """parse a string-based _colspec into its component parts.""" + + m = self._colspec.split('.') + if m is None: + raise exc.ArgumentError( + "Invalid foreign key column specification: %s" % + self._colspec) + if (len(m) == 1): + tname = m.pop() + colname = None + else: + colname = m.pop() + tname = m.pop() + + # A FK between column 'bar' and table 'foo' can be + # specified as 'foo', 'foo.bar', 'dbo.foo.bar', + # 'otherdb.dbo.foo.bar'. Once we have the column name and + # the table name, treat everything else as the schema + # name. Some databases (e.g. Sybase) support + # inter-database foreign keys. See tickets#1341 and -- + # indirectly related -- Ticket #594. This assumes that '.' + # will never appear *within* any component of the FK. + + if (len(m) > 0): + schema = '.'.join(m) + else: + schema = None + return schema, tname, colname + + def _table_key(self): + if isinstance(self._colspec, util.string_types): + schema, tname, colname = self._column_tokens + return _get_table_key(tname, schema) + elif hasattr(self._colspec, '__clause_element__'): + _column = self._colspec.__clause_element__() + else: + _column = self._colspec + + if _column.table is None: + return None + else: + return _column.table.key + + def _resolve_col_tokens(self): + if self.parent is None: + raise exc.InvalidRequestError( + "this ForeignKey object does not yet have a " + "parent Column associated with it.") + + elif self.parent.table is None: + raise exc.InvalidRequestError( + "this ForeignKey's parent column is not yet associated " + "with a Table.") + + parenttable = self.parent.table + + # assertion, can be commented out. + # basically Column._make_proxy() sends the actual + # target Column to the ForeignKey object, so the + # string resolution here is never called. + for c in self.parent.base_columns: + if isinstance(c, Column): + assert c.table is parenttable + break + else: + assert False + ###################### + + schema, tname, colname = self._column_tokens + + if schema is None and parenttable.metadata.schema is not None: + schema = parenttable.metadata.schema + + tablekey = _get_table_key(tname, schema) + return parenttable, tablekey, colname + + + def _link_to_col_by_colstring(self, parenttable, table, colname): + if not hasattr(self.constraint, '_referred_table'): + self.constraint._referred_table = table + else: + assert self.constraint._referred_table is table + + _column = None + if colname is None: + # colname is None in the case that ForeignKey argument + # was specified as table name only, in which case we + # match the column name to the same column on the + # parent. + key = self.parent + _column = table.c.get(self.parent.key, None) + elif self.link_to_name: + key = colname + for c in table.c: + if c.name == colname: + _column = c + else: + key = colname + _column = table.c.get(colname, None) + + if _column is None: + raise exc.NoReferencedColumnError( + "Could not initialize target column for ForeignKey '%s' on table '%s': " + "table '%s' has no column named '%s'" % ( + self._colspec, parenttable.name, table.name, key), + table.name, key) + + self._set_target_column(_column) + + def _set_target_column(self, column): + # propagate TypeEngine to parent if it didn't have one + if self.parent.type._isnull: + self.parent.type = column.type + + # super-edgy case, if other FKs point to our column, + # they'd get the type propagated out also. + if isinstance(self.parent.table, Table): + fk_key = (self.parent.table.key, self.parent.key) + if fk_key in self.parent.table.metadata._fk_memos: + for fk in self.parent.table.metadata._fk_memos[fk_key]: + if fk.parent.type._isnull: + fk.parent.type = column.type + + self.column = column + + @util.memoized_property + def column(self): + """Return the target :class:`.Column` referenced by this + :class:`.ForeignKey`. + + If no target column has been established, an exception + is raised. + + .. versionchanged:: 0.9.0 + Foreign key target column resolution now occurs as soon as both + the ForeignKey object and the remote Column to which it refers + are both associated with the same MetaData object. + + """ + + if isinstance(self._colspec, util.string_types): + + parenttable, tablekey, colname = self._resolve_col_tokens() + + if tablekey not in parenttable.metadata: + raise exc.NoReferencedTableError( + "Foreign key associated with column '%s' could not find " + "table '%s' with which to generate a " + "foreign key to target column '%s'" % + (self.parent, tablekey, colname), + tablekey) + elif parenttable.key not in parenttable.metadata: + raise exc.InvalidRequestError( + "Table %s is no longer associated with its " + "parent MetaData" % parenttable) + else: + raise exc.NoReferencedColumnError( + "Could not initialize target column for " + "ForeignKey '%s' on table '%s': " + "table '%s' has no column named '%s'" % ( + self._colspec, parenttable.name, tablekey, colname), + tablekey, colname) + elif hasattr(self._colspec, '__clause_element__'): + _column = self._colspec.__clause_element__() + return _column + else: + _column = self._colspec + return _column + + def _set_parent(self, column): + if self.parent is not None and self.parent is not column: + raise exc.InvalidRequestError( + "This ForeignKey already has a parent !") + self.parent = column + self.parent.foreign_keys.add(self) + self.parent._on_table_attach(self._set_table) + + def _set_remote_table(self, table): + parenttable, tablekey, colname = self._resolve_col_tokens() + self._link_to_col_by_colstring(parenttable, table, colname) + self.constraint._validate_dest_table(table) + + def _remove_from_metadata(self, metadata): + parenttable, table_key, colname = self._resolve_col_tokens() + fk_key = (table_key, colname) + + if self in metadata._fk_memos[fk_key]: + # TODO: no test coverage for self not in memos + metadata._fk_memos[fk_key].remove(self) + + def _set_table(self, column, table): + # standalone ForeignKey - create ForeignKeyConstraint + # on the hosting Table when attached to the Table. + if self.constraint is None and isinstance(table, Table): + self.constraint = ForeignKeyConstraint( + [], [], use_alter=self.use_alter, name=self.name, + onupdate=self.onupdate, ondelete=self.ondelete, + deferrable=self.deferrable, initially=self.initially, + match=self.match, + ) + self.constraint._elements[self.parent] = self + self.constraint._set_parent_with_dispatch(table) + table.foreign_keys.add(self) + + # set up remote ".column" attribute, or a note to pick it + # up when the other Table/Column shows up + if isinstance(self._colspec, util.string_types): + parenttable, table_key, colname = self._resolve_col_tokens() + fk_key = (table_key, colname) + if table_key in parenttable.metadata.tables: + table = parenttable.metadata.tables[table_key] + try: + self._link_to_col_by_colstring(parenttable, table, colname) + except exc.NoReferencedColumnError: + # this is OK, we'll try later + pass + parenttable.metadata._fk_memos[fk_key].append(self) + elif hasattr(self._colspec, '__clause_element__'): + _column = self._colspec.__clause_element__() + self._set_target_column(_column) + else: + _column = self._colspec + self._set_target_column(_column) + + + +class _NotAColumnExpr(object): + def _not_a_column_expr(self): + raise exc.InvalidRequestError( + "This %s cannot be used directly " + "as a column expression." % self.__class__.__name__) + + __clause_element__ = self_group = lambda self: self._not_a_column_expr() + _from_objects = property(lambda self: self._not_a_column_expr()) + + +class DefaultGenerator(_NotAColumnExpr, SchemaItem): + """Base class for column *default* values.""" + + __visit_name__ = 'default_generator' + + is_sequence = False + is_server_default = False + column = None + + def __init__(self, for_update=False): + self.for_update = for_update + + def _set_parent(self, column): + self.column = column + if self.for_update: + self.column.onupdate = self + else: + self.column.default = self + + def execute(self, bind=None, **kwargs): + if bind is None: + bind = _bind_or_error(self) + return bind._execute_default(self, **kwargs) + + @property + def bind(self): + """Return the connectable associated with this default.""" + if getattr(self, 'column', None) is not None: + return self.column.table.bind + else: + return None + + +class ColumnDefault(DefaultGenerator): + """A plain default value on a column. + + This could correspond to a constant, a callable function, + or a SQL clause. + + :class:`.ColumnDefault` is generated automatically + whenever the ``default``, ``onupdate`` arguments of + :class:`.Column` are used. A :class:`.ColumnDefault` + can be passed positionally as well. + + For example, the following:: + + Column('foo', Integer, default=50) + + Is equivalent to:: + + Column('foo', Integer, ColumnDefault(50)) + + + """ + + def __init__(self, arg, **kwargs): + """"Construct a new :class:`.ColumnDefault`. + + + :param arg: argument representing the default value. + May be one of the following: + + * a plain non-callable Python value, such as a + string, integer, boolean, or other simple type. + The default value will be used as is each time. + * a SQL expression, that is one which derives from + :class:`.ColumnElement`. The SQL expression will + be rendered into the INSERT or UPDATE statement, + or in the case of a primary key column when + RETURNING is not used may be + pre-executed before an INSERT within a SELECT. + * A Python callable. The function will be invoked for each + new row subject to an INSERT or UPDATE. + The callable must accept exactly + zero or one positional arguments. The one-argument form + will receive an instance of the :class:`.ExecutionContext`, + which provides contextual information as to the current + :class:`.Connection` in use as well as the current + statement and parameters. + + """ + super(ColumnDefault, self).__init__(**kwargs) + if isinstance(arg, FetchedValue): + raise exc.ArgumentError( + "ColumnDefault may not be a server-side default type.") + if util.callable(arg): + arg = self._maybe_wrap_callable(arg) + self.arg = arg + + @util.memoized_property + def is_callable(self): + return util.callable(self.arg) + + @util.memoized_property + def is_clause_element(self): + return isinstance(self.arg, ClauseElement) + + @util.memoized_property + def is_scalar(self): + return not self.is_callable and \ + not self.is_clause_element and \ + not self.is_sequence + + def _maybe_wrap_callable(self, fn): + """Wrap callables that don't accept a context. + + The alternative here is to require that + a simple callable passed to "default" would need + to be of the form "default=lambda ctx: datetime.now". + That is the more "correct" way to go, but the case + of using a zero-arg callable for "default" is so + much more prominent than the context-specific one + I'm having trouble justifying putting that inconvenience + on everyone. + + """ + if inspect.isfunction(fn): + inspectable = fn + elif inspect.isclass(fn): + inspectable = fn.__init__ + elif hasattr(fn, '__call__'): + inspectable = fn.__call__ + else: + # probably not inspectable, try anyways. + inspectable = fn + try: + argspec = inspect.getargspec(inspectable) + except TypeError: + return lambda ctx: fn() + + defaulted = argspec[3] is not None and len(argspec[3]) or 0 + positionals = len(argspec[0]) - defaulted + + # Py3K compat - no unbound methods + if inspect.ismethod(inspectable) or inspect.isclass(fn): + positionals -= 1 + + if positionals == 0: + return lambda ctx: fn() + elif positionals == 1: + return fn + else: + raise exc.ArgumentError( + "ColumnDefault Python function takes zero or one " + "positional arguments") + + def _visit_name(self): + if self.for_update: + return "column_onupdate" + else: + return "column_default" + __visit_name__ = property(_visit_name) + + def __repr__(self): + return "ColumnDefault(%r)" % self.arg + + +class Sequence(DefaultGenerator): + """Represents a named database sequence. + + The :class:`.Sequence` object represents the name and configurational + parameters of a database sequence. It also represents + a construct that can be "executed" by a SQLAlchemy :class:`.Engine` + or :class:`.Connection`, rendering the appropriate "next value" function + for the target database and returning a result. + + The :class:`.Sequence` is typically associated with a primary key column:: + + some_table = Table('some_table', metadata, + Column('id', Integer, Sequence('some_table_seq'), primary_key=True) + ) + + When CREATE TABLE is emitted for the above :class:`.Table`, if the + target platform supports sequences, a CREATE SEQUENCE statement will + be emitted as well. For platforms that don't support sequences, + the :class:`.Sequence` construct is ignored. + + See also: :class:`.CreateSequence` :class:`.DropSequence` + + """ + + __visit_name__ = 'sequence' + + is_sequence = True + + def __init__(self, name, start=None, increment=None, schema=None, + optional=False, quote=None, metadata=None, + quote_schema=None, + for_update=False): + """Construct a :class:`.Sequence` object. + + :param name: The name of the sequence. + :param start: the starting index of the sequence. This value is + used when the CREATE SEQUENCE command is emitted to the database + as the value of the "START WITH" clause. If ``None``, the + clause is omitted, which on most platforms indicates a starting + value of 1. + :param increment: the increment value of the sequence. This + value is used when the CREATE SEQUENCE command is emitted to + the database as the value of the "INCREMENT BY" clause. If ``None``, + the clause is omitted, which on most platforms indicates an + increment of 1. + :param schema: Optional schema name for the sequence, if located + in a schema other than the default. + :param optional: boolean value, when ``True``, indicates that this + :class:`.Sequence` object only needs to be explicitly generated + on backends that don't provide another way to generate primary + key identifiers. Currently, it essentially means, "don't create + this sequence on the Postgresql backend, where the SERIAL keyword + creates a sequence for us automatically". + :param quote: boolean value, when ``True`` or ``False``, explicitly + forces quoting of the schema name on or off. When left at its + default of ``None``, normal quoting rules based on casing and reserved + words take place. + :param metadata: optional :class:`.MetaData` object which will be + associated with this :class:`.Sequence`. A :class:`.Sequence` + that is associated with a :class:`.MetaData` gains access to the + ``bind`` of that :class:`.MetaData`, meaning the + :meth:`.Sequence.create` and :meth:`.Sequence.drop` methods will + make usage of that engine automatically. + + .. versionchanged:: 0.7 + Additionally, the appropriate CREATE SEQUENCE/ + DROP SEQUENCE DDL commands will be emitted corresponding to this + :class:`.Sequence` when :meth:`.MetaData.create_all` and + :meth:`.MetaData.drop_all` are invoked. + + Note that when a :class:`.Sequence` is applied to a :class:`.Column`, + the :class:`.Sequence` is automatically associated with the + :class:`.MetaData` object of that column's parent :class:`.Table`, + when that association is made. The :class:`.Sequence` will then + be subject to automatic CREATE SEQUENCE/DROP SEQUENCE corresponding + to when the :class:`.Table` object itself is created or dropped, + rather than that of the :class:`.MetaData` object overall. + :param for_update: Indicates this :class:`.Sequence`, when associated + with a :class:`.Column`, should be invoked for UPDATE statements + on that column's table, rather than for INSERT statements, when + no value is otherwise present for that column in the statement. + + """ + super(Sequence, self).__init__(for_update=for_update) + self.name = name + self.start = start + self.increment = increment + self.optional = optional + self.quote = quote + if metadata is not None and schema is None and metadata.schema: + self.schema = schema = metadata.schema + self.quote_schema = metadata.quote_schema + else: + self.schema = schema + self.quote_schema = quote_schema + self.metadata = metadata + self._key = _get_table_key(name, schema) + if metadata: + self._set_metadata(metadata) + + @util.memoized_property + def is_callable(self): + return False + + @util.memoized_property + def is_clause_element(self): + return False + + @util.dependencies("sqlalchemy.sql.functions.func") + def next_value(self, func): + """Return a :class:`.next_value` function element + which will render the appropriate increment function + for this :class:`.Sequence` within any SQL expression. + + """ + return func.next_value(self, bind=self.bind) + + def _set_parent(self, column): + super(Sequence, self)._set_parent(column) + column._on_table_attach(self._set_table) + + def _set_table(self, column, table): + self._set_metadata(table.metadata) + + def _set_metadata(self, metadata): + self.metadata = metadata + self.metadata._sequences[self._key] = self + + @property + def bind(self): + if self.metadata: + return self.metadata.bind + else: + return None + + def create(self, bind=None, checkfirst=True): + """Creates this sequence in the database.""" + + if bind is None: + bind = _bind_or_error(self) + bind._run_visitor(ddl.SchemaGenerator, + self, + checkfirst=checkfirst) + + def drop(self, bind=None, checkfirst=True): + """Drops this sequence from the database.""" + + if bind is None: + bind = _bind_or_error(self) + bind._run_visitor(ddl.SchemaDropper, + self, + checkfirst=checkfirst) + + def _not_a_column_expr(self): + raise exc.InvalidRequestError( + "This %s cannot be used directly " + "as a column expression. Use func.next_value(sequence) " + "to produce a 'next value' function that's usable " + "as a column element." + % self.__class__.__name__) + + +@inspection._self_inspects +class FetchedValue(_NotAColumnExpr, SchemaEventTarget): + """A marker for a transparent database-side default. + + Use :class:`.FetchedValue` when the database is configured + to provide some automatic default for a column. + + E.g.:: + + Column('foo', Integer, FetchedValue()) + + Would indicate that some trigger or default generator + will create a new value for the ``foo`` column during an + INSERT. + + .. seealso:: + + :ref:`triggered_columns` + + """ + is_server_default = True + reflected = False + has_argument = False + + def __init__(self, for_update=False): + self.for_update = for_update + + def _as_for_update(self, for_update): + if for_update == self.for_update: + return self + else: + return self._clone(for_update) + + def _clone(self, for_update): + n = self.__class__.__new__(self.__class__) + n.__dict__.update(self.__dict__) + n.__dict__.pop('column', None) + n.for_update = for_update + return n + + def _set_parent(self, column): + self.column = column + if self.for_update: + self.column.server_onupdate = self + else: + self.column.server_default = self + + def __repr__(self): + return util.generic_repr(self) + + +class DefaultClause(FetchedValue): + """A DDL-specified DEFAULT column value. + + :class:`.DefaultClause` is a :class:`.FetchedValue` + that also generates a "DEFAULT" clause when + "CREATE TABLE" is emitted. + + :class:`.DefaultClause` is generated automatically + whenever the ``server_default``, ``server_onupdate`` arguments of + :class:`.Column` are used. A :class:`.DefaultClause` + can be passed positionally as well. + + For example, the following:: + + Column('foo', Integer, server_default="50") + + Is equivalent to:: + + Column('foo', Integer, DefaultClause("50")) + + """ + + has_argument = True + + def __init__(self, arg, for_update=False, _reflected=False): + util.assert_arg_type(arg, (util.string_types[0], + ClauseElement, + TextClause), 'arg') + super(DefaultClause, self).__init__(for_update) + self.arg = arg + self.reflected = _reflected + + def __repr__(self): + return "DefaultClause(%r, for_update=%r)" % \ + (self.arg, self.for_update) + + +class PassiveDefault(DefaultClause): + """A DDL-specified DEFAULT column value. + + .. deprecated:: 0.6 + :class:`.PassiveDefault` is deprecated. + Use :class:`.DefaultClause`. + """ + @util.deprecated("0.6", + ":class:`.PassiveDefault` is deprecated. " + "Use :class:`.DefaultClause`.", + False) + def __init__(self, *arg, **kw): + DefaultClause.__init__(self, *arg, **kw) + + +class Constraint(SchemaItem): + """A table-level SQL constraint.""" + + __visit_name__ = 'constraint' + + def __init__(self, name=None, deferrable=None, initially=None, + _create_rule=None, + **kw): + """Create a SQL constraint. + + :param name: + Optional, the in-database name of this ``Constraint``. + + :param deferrable: + Optional bool. If set, emit DEFERRABLE or NOT DEFERRABLE when + issuing DDL for this constraint. + + :param initially: + Optional string. If set, emit INITIALLY when issuing DDL + for this constraint. + + :param _create_rule: + a callable which is passed the DDLCompiler object during + compilation. Returns True or False to signal inline generation of + this Constraint. + + The AddConstraint and DropConstraint DDL constructs provide + DDLElement's more comprehensive "conditional DDL" approach that is + passed a database connection when DDL is being issued. _create_rule + is instead called during any CREATE TABLE compilation, where there + may not be any transaction/connection in progress. However, it + allows conditional compilation of the constraint even for backends + which do not support addition of constraints through ALTER TABLE, + which currently includes SQLite. + + _create_rule is used by some types to create constraints. + Currently, its call signature is subject to change at any time. + + :param \**kwargs: + Dialect-specific keyword parameters, see the documentation + for various dialects and constraints regarding options here. + + """ + + self.name = name + self.deferrable = deferrable + self.initially = initially + self._create_rule = _create_rule + util.set_creation_order(self) + _validate_dialect_kwargs(kw, self.__class__.__name__) + self.kwargs = kw + + @property + def table(self): + try: + if isinstance(self.parent, Table): + return self.parent + except AttributeError: + pass + raise exc.InvalidRequestError( + "This constraint is not bound to a table. Did you " + "mean to call table.append_constraint(constraint) ?") + + def _set_parent(self, parent): + self.parent = parent + parent.constraints.add(self) + + def copy(self, **kw): + raise NotImplementedError() + + +def _to_schema_column(element): + if hasattr(element, '__clause_element__'): + element = element.__clause_element__() + if not isinstance(element, Column): + raise exc.ArgumentError("schema.Column object expected") + return element + + +def _to_schema_column_or_string(element): + if hasattr(element, '__clause_element__'): + element = element.__clause_element__() + if not isinstance(element, util.string_types + (ColumnElement, )): + msg = "Element %r is not a string name or column element" + raise exc.ArgumentError(msg % element) + return element + + +class ColumnCollectionMixin(object): + def __init__(self, *columns): + self.columns = ColumnCollection() + self._pending_colargs = [_to_schema_column_or_string(c) + for c in columns] + if self._pending_colargs and \ + isinstance(self._pending_colargs[0], Column) and \ + isinstance(self._pending_colargs[0].table, Table): + self._set_parent_with_dispatch(self._pending_colargs[0].table) + + def _set_parent(self, table): + for col in self._pending_colargs: + if isinstance(col, util.string_types): + col = table.c[col] + self.columns.add(col) + + +class ColumnCollectionConstraint(ColumnCollectionMixin, Constraint): + """A constraint that proxies a ColumnCollection.""" + + def __init__(self, *columns, **kw): + """ + :param \*columns: + A sequence of column names or Column objects. + + :param name: + Optional, the in-database name of this constraint. + + :param deferrable: + Optional bool. If set, emit DEFERRABLE or NOT DEFERRABLE when + issuing DDL for this constraint. + + :param initially: + Optional string. If set, emit INITIALLY when issuing DDL + for this constraint. + + """ + ColumnCollectionMixin.__init__(self, *columns) + Constraint.__init__(self, **kw) + + def _set_parent(self, table): + ColumnCollectionMixin._set_parent(self, table) + Constraint._set_parent(self, table) + + def __contains__(self, x): + return x in self.columns + + def copy(self, **kw): + c = self.__class__(name=self.name, deferrable=self.deferrable, + initially=self.initially, *self.columns.keys()) + c.dispatch._update(self.dispatch) + return c + + def contains_column(self, col): + return self.columns.contains_column(col) + + def __iter__(self): + # inlining of + # return iter(self.columns) + # ColumnCollection->OrderedProperties->OrderedDict + ordered_dict = self.columns._data + return (ordered_dict[key] for key in ordered_dict._list) + + def __len__(self): + return len(self.columns._data) + + +class CheckConstraint(Constraint): + """A table- or column-level CHECK constraint. + + Can be included in the definition of a Table or Column. + """ + + def __init__(self, sqltext, name=None, deferrable=None, + initially=None, table=None, _create_rule=None, + _autoattach=True): + """Construct a CHECK constraint. + + :param sqltext: + A string containing the constraint definition, which will be used + verbatim, or a SQL expression construct. + + :param name: + Optional, the in-database name of the constraint. + + :param deferrable: + Optional bool. If set, emit DEFERRABLE or NOT DEFERRABLE when + issuing DDL for this constraint. + + :param initially: + Optional string. If set, emit INITIALLY when issuing DDL + for this constraint. + + """ + + super(CheckConstraint, self).\ + __init__(name, deferrable, initially, _create_rule) + self.sqltext = _literal_as_text(sqltext) + if table is not None: + self._set_parent_with_dispatch(table) + elif _autoattach: + cols = _find_columns(self.sqltext) + tables = set([c.table for c in cols + if isinstance(c.table, Table)]) + if len(tables) == 1: + self._set_parent_with_dispatch( + tables.pop()) + + def __visit_name__(self): + if isinstance(self.parent, Table): + return "check_constraint" + else: + return "column_check_constraint" + __visit_name__ = property(__visit_name__) + + def copy(self, target_table=None, **kw): + if target_table is not None: + def replace(col): + if self.table.c.contains_column(col): + return target_table.c[col.key] + else: + return None + sqltext = visitors.replacement_traverse(self.sqltext, {}, replace) + else: + sqltext = self.sqltext + c = CheckConstraint(sqltext, + name=self.name, + initially=self.initially, + deferrable=self.deferrable, + _create_rule=self._create_rule, + table=target_table, + _autoattach=False) + c.dispatch._update(self.dispatch) + return c + + +class ForeignKeyConstraint(Constraint): + """A table-level FOREIGN KEY constraint. + + Defines a single column or composite FOREIGN KEY ... REFERENCES + constraint. For a no-frills, single column foreign key, adding a + :class:`.ForeignKey` to the definition of a :class:`.Column` is a shorthand + equivalent for an unnamed, single column :class:`.ForeignKeyConstraint`. + + Examples of foreign key configuration are in :ref:`metadata_foreignkeys`. + + """ + __visit_name__ = 'foreign_key_constraint' + + def __init__(self, columns, refcolumns, name=None, onupdate=None, + ondelete=None, deferrable=None, initially=None, use_alter=False, + link_to_name=False, match=None, table=None): + """Construct a composite-capable FOREIGN KEY. + + :param columns: A sequence of local column names. The named columns + must be defined and present in the parent Table. The names should + match the ``key`` given to each column (defaults to the name) unless + ``link_to_name`` is True. + + :param refcolumns: A sequence of foreign column names or Column + objects. The columns must all be located within the same Table. + + :param name: Optional, the in-database name of the key. + + :param onupdate: Optional string. If set, emit ON UPDATE when + issuing DDL for this constraint. Typical values include CASCADE, + DELETE and RESTRICT. + + :param ondelete: Optional string. If set, emit ON DELETE when + issuing DDL for this constraint. Typical values include CASCADE, + DELETE and RESTRICT. + + :param deferrable: Optional bool. If set, emit DEFERRABLE or NOT + DEFERRABLE when issuing DDL for this constraint. + + :param initially: Optional string. If set, emit INITIALLY when + issuing DDL for this constraint. + + :param link_to_name: if True, the string name given in ``column`` is + the rendered name of the referenced column, not its locally assigned + ``key``. + + :param use_alter: If True, do not emit the DDL for this constraint as + part of the CREATE TABLE definition. Instead, generate it via an + ALTER TABLE statement issued after the full collection of tables + have been created, and drop it via an ALTER TABLE statement before + the full collection of tables are dropped. This is shorthand for the + usage of :class:`.AddConstraint` and :class:`.DropConstraint` applied + as "after-create" and "before-drop" events on the MetaData object. + This is normally used to generate/drop constraints on objects that + are mutually dependent on each other. + + :param match: Optional string. If set, emit MATCH when issuing + DDL for this constraint. Typical values include SIMPLE, PARTIAL + and FULL. + + """ + super(ForeignKeyConstraint, self).\ + __init__(name, deferrable, initially) + + self.onupdate = onupdate + self.ondelete = ondelete + self.link_to_name = link_to_name + if self.name is None and use_alter: + raise exc.ArgumentError("Alterable Constraint requires a name") + self.use_alter = use_alter + self.match = match + + self._elements = util.OrderedDict() + + # standalone ForeignKeyConstraint - create + # associated ForeignKey objects which will be applied to hosted + # Column objects (in col.foreign_keys), either now or when attached + # to the Table for string-specified names + for col, refcol in zip(columns, refcolumns): + self._elements[col] = ForeignKey( + refcol, + _constraint=self, + name=self.name, + onupdate=self.onupdate, + ondelete=self.ondelete, + use_alter=self.use_alter, + link_to_name=self.link_to_name, + match=self.match + ) + + if table is not None: + self._set_parent_with_dispatch(table) + elif columns and \ + isinstance(columns[0], Column) and \ + columns[0].table is not None: + self._set_parent_with_dispatch(columns[0].table) + + def _validate_dest_table(self, table): + table_keys = set([elem._table_key() for elem in self._elements.values()]) + if None not in table_keys and len(table_keys) > 1: + elem0, elem1 = sorted(table_keys)[0:2] + raise exc.ArgumentError( + 'ForeignKeyConstraint on %s(%s) refers to ' + 'multiple remote tables: %s and %s' % ( + table.fullname, + self._col_description, + elem0, + elem1 + )) + + @property + def _col_description(self): + return ", ".join(self._elements) + + @property + def columns(self): + return list(self._elements) + + @property + def elements(self): + return list(self._elements.values()) + + def _set_parent(self, table): + super(ForeignKeyConstraint, self)._set_parent(table) + + self._validate_dest_table(table) + + for col, fk in self._elements.items(): + # string-specified column names now get + # resolved to Column objects + if isinstance(col, util.string_types): + try: + col = table.c[col] + except KeyError: + raise exc.ArgumentError( + "Can't create ForeignKeyConstraint " + "on table '%s': no column " + "named '%s' is present." % (table.description, col)) + + if not hasattr(fk, 'parent') or \ + fk.parent is not col: + fk._set_parent_with_dispatch(col) + + if self.use_alter: + def supports_alter(ddl, event, schema_item, bind, **kw): + return table in set(kw['tables']) and \ + bind.dialect.supports_alter + + event.listen(table.metadata, "after_create", + ddl.AddConstraint(self, on=supports_alter)) + event.listen(table.metadata, "before_drop", + ddl.DropConstraint(self, on=supports_alter)) + + def copy(self, schema=None, **kw): + fkc = ForeignKeyConstraint( + [x.parent.key for x in self._elements.values()], + [x._get_colspec(schema=schema) for x in self._elements.values()], + name=self.name, + onupdate=self.onupdate, + ondelete=self.ondelete, + use_alter=self.use_alter, + deferrable=self.deferrable, + initially=self.initially, + link_to_name=self.link_to_name, + match=self.match + ) + fkc.dispatch._update(self.dispatch) + return fkc + + +class PrimaryKeyConstraint(ColumnCollectionConstraint): + """A table-level PRIMARY KEY constraint. + + Defines a single column or composite PRIMARY KEY constraint. For a + no-frills primary key, adding ``primary_key=True`` to one or more + ``Column`` definitions is a shorthand equivalent for an unnamed single- or + multiple-column PrimaryKeyConstraint. + """ + + __visit_name__ = 'primary_key_constraint' + + def _set_parent(self, table): + super(PrimaryKeyConstraint, self)._set_parent(table) + + if table.primary_key in table.constraints: + table.constraints.remove(table.primary_key) + table.primary_key = self + table.constraints.add(self) + + for c in self.columns: + c.primary_key = True + + def _replace(self, col): + self.columns.replace(col) + + +class UniqueConstraint(ColumnCollectionConstraint): + """A table-level UNIQUE constraint. + + Defines a single column or composite UNIQUE constraint. For a no-frills, + single column constraint, adding ``unique=True`` to the ``Column`` + definition is a shorthand equivalent for an unnamed, single column + UniqueConstraint. + """ + + __visit_name__ = 'unique_constraint' + + +class Index(ColumnCollectionMixin, SchemaItem): + """A table-level INDEX. + + Defines a composite (one or more column) INDEX. + + E.g.:: + + sometable = Table("sometable", metadata, + Column("name", String(50)), + Column("address", String(100)) + ) + + Index("some_index", sometable.c.name) + + For a no-frills, single column index, adding + :class:`.Column` also supports ``index=True``:: + + sometable = Table("sometable", metadata, + Column("name", String(50), index=True) + ) + + For a composite index, multiple columns can be specified:: + + Index("some_index", sometable.c.name, sometable.c.address) + + Functional indexes are supported as well, keeping in mind that at least + one :class:`.Column` must be present:: + + Index("some_index", func.lower(sometable.c.name)) + + .. versionadded:: 0.8 support for functional and expression-based indexes. + + .. seealso:: + + :ref:`schema_indexes` - General information on :class:`.Index`. + + :ref:`postgresql_indexes` - PostgreSQL-specific options available for the + :class:`.Index` construct. + + :ref:`mysql_indexes` - MySQL-specific options available for the + :class:`.Index` construct. + + :ref:`mssql_indexes` - MSSQL-specific options available for the + :class:`.Index` construct. + + """ + + __visit_name__ = 'index' + + def __init__(self, name, *expressions, **kw): + """Construct an index object. + + :param name: + The name of the index + + :param \*expressions: Column or SQL expressions. + + :param unique: + Defaults to False: create a unique index. + + :param \**kw: + Other keyword arguments may be interpreted by specific dialects. + + """ + self.table = None + + columns = [] + for expr in expressions: + if not isinstance(expr, ClauseElement): + columns.append(expr) + else: + cols = [] + visitors.traverse(expr, {}, {'column': cols.append}) + if cols: + columns.append(cols[0]) + else: + columns.append(expr) + + self.expressions = expressions + + # will call _set_parent() if table-bound column + # objects are present + ColumnCollectionMixin.__init__(self, *columns) + + self.name = name + self.unique = kw.pop('unique', False) + self.kwargs = kw + + def _set_parent(self, table): + ColumnCollectionMixin._set_parent(self, table) + + if self.table is not None and table is not self.table: + raise exc.ArgumentError( + "Index '%s' is against table '%s', and " + "cannot be associated with table '%s'." % ( + self.name, + self.table.description, + table.description + ) + ) + self.table = table + for c in self.columns: + if c.table != self.table: + raise exc.ArgumentError( + "Column '%s' is not part of table '%s'." % + (c, self.table.description) + ) + table.indexes.add(self) + + self.expressions = [ + expr if isinstance(expr, ClauseElement) + else colexpr + for expr, colexpr in zip(self.expressions, self.columns) + ] + + @property + def bind(self): + """Return the connectable associated with this Index.""" + + return self.table.bind + + def create(self, bind=None): + """Issue a ``CREATE`` statement for this + :class:`.Index`, using the given :class:`.Connectable` + for connectivity. + + See also :meth:`.MetaData.create_all`. + + """ + if bind is None: + bind = _bind_or_error(self) + bind._run_visitor(ddl.SchemaGenerator, self) + return self + + def drop(self, bind=None): + """Issue a ``DROP`` statement for this + :class:`.Index`, using the given :class:`.Connectable` + for connectivity. + + See also :meth:`.MetaData.drop_all`. + + """ + if bind is None: + bind = _bind_or_error(self) + bind._run_visitor(ddl.SchemaDropper, self) + + def __repr__(self): + return 'Index(%s)' % ( + ", ".join( + [repr(self.name)] + + [repr(c) for c in self.columns] + + (self.unique and ["unique=True"] or []) + )) + + +class MetaData(SchemaItem): + """A collection of :class:`.Table` objects and their associated schema + constructs. + + Holds a collection of :class:`.Table` objects as well as + an optional binding to an :class:`.Engine` or + :class:`.Connection`. If bound, the :class:`.Table` objects + in the collection and their columns may participate in implicit SQL + execution. + + The :class:`.Table` objects themselves are stored in the + ``metadata.tables`` dictionary. + + The ``bind`` property may be assigned to dynamically. A common pattern is + to start unbound and then bind later when an engine is available:: + + metadata = MetaData() + # define tables + Table('mytable', metadata, ...) + # connect to an engine later, perhaps after loading a URL from a + # configuration file + metadata.bind = an_engine + + MetaData is a thread-safe object after tables have been explicitly defined + or loaded via reflection. + + See also: + + :ref:`metadata_describing` - Introduction to database metadata + + .. index:: + single: thread safety; MetaData + + """ + + __visit_name__ = 'metadata' + + def __init__(self, bind=None, reflect=False, schema=None, + quote_schema=None): + """Create a new MetaData object. + + :param bind: + An Engine or Connection to bind to. May also be a string or URL + instance, these are passed to create_engine() and this MetaData will + be bound to the resulting engine. + + :param reflect: + Optional, automatically load all tables from the bound database. + Defaults to False. ``bind`` is required when this option is set. + + .. deprecated:: 0.8 + Please use the :meth:`.MetaData.reflect` method. + + :param schema: + The default schema to use for the :class:`.Table`, + :class:`.Sequence`, and other objects associated with this + :class:`.MetaData`. Defaults to ``None``. + + :param quote_schema: + Sets the ``quote_schema`` flag for those :class:`.Table`, + :class:`.Sequence`, and other objects which make usage of the + local ``schema`` name. + + .. versionadded:: 0.7.4 + ``schema`` and ``quote_schema`` parameters. + + """ + self.tables = util.immutabledict() + self.schema = schema + self.quote_schema = quote_schema + self._schemas = set() + self._sequences = {} + self._fk_memos = collections.defaultdict(list) + + self.bind = bind + if reflect: + util.warn("reflect=True is deprecate; please " + "use the reflect() method.") + if not bind: + raise exc.ArgumentError( + "A bind must be supplied in conjunction " + "with reflect=True") + self.reflect() + + def __repr__(self): + return 'MetaData(bind=%r)' % self.bind + + def __contains__(self, table_or_key): + if not isinstance(table_or_key, util.string_types): + table_or_key = table_or_key.key + return table_or_key in self.tables + + def _add_table(self, name, schema, table): + key = _get_table_key(name, schema) + dict.__setitem__(self.tables, key, table) + if schema: + self._schemas.add(schema) + + + + def _remove_table(self, name, schema): + key = _get_table_key(name, schema) + removed = dict.pop(self.tables, key, None) + if removed is not None: + for fk in removed.foreign_keys: + fk._remove_from_metadata(self) + if self._schemas: + self._schemas = set([t.schema + for t in self.tables.values() + if t.schema is not None]) + + + def __getstate__(self): + return {'tables': self.tables, + 'schema': self.schema, + 'quote_schema': self.quote_schema, + 'schemas': self._schemas, + 'sequences': self._sequences, + 'fk_memos': self._fk_memos} + + def __setstate__(self, state): + self.tables = state['tables'] + self.schema = state['schema'] + self.quote_schema = state['quote_schema'] + self._bind = None + self._sequences = state['sequences'] + self._schemas = state['schemas'] + self._fk_memos = state['fk_memos'] + + def is_bound(self): + """True if this MetaData is bound to an Engine or Connection.""" + + return self._bind is not None + + def bind(self): + """An :class:`.Engine` or :class:`.Connection` to which this + :class:`.MetaData` is bound. + + Typically, a :class:`.Engine` is assigned to this attribute + so that "implicit execution" may be used, or alternatively + as a means of providing engine binding information to an + ORM :class:`.Session` object:: + + engine = create_engine("someurl://") + metadata.bind = engine + + .. seealso:: + + :ref:`dbengine_implicit` - background on "bound metadata" + + """ + return self._bind + + @util.dependencies("sqlalchemy.engine.url") + def _bind_to(self, url, bind): + """Bind this MetaData to an Engine, Connection, string or URL.""" + + if isinstance(bind, util.string_types + (url.URL, )): + self._bind = sqlalchemy.create_engine(bind) + else: + self._bind = bind + bind = property(bind, _bind_to) + + def clear(self): + """Clear all Table objects from this MetaData.""" + + dict.clear(self.tables) + self._schemas.clear() + self._fk_memos.clear() + + def remove(self, table): + """Remove the given Table object from this MetaData.""" + + self._remove_table(table.name, table.schema) + + @property + def sorted_tables(self): + """Returns a list of :class:`.Table` objects sorted in order of + foreign key dependency. + + The sorting will place :class:`.Table` objects that have dependencies + first, before the dependencies themselves, representing the + order in which they can be created. To get the order in which + the tables would be dropped, use the ``reversed()`` Python built-in. + + .. seealso:: + + :meth:`.Inspector.sorted_tables` + + """ + return ddl.sort_tables(self.tables.values()) + + def reflect(self, bind=None, schema=None, views=False, only=None): + """Load all available table definitions from the database. + + Automatically creates ``Table`` entries in this ``MetaData`` for any + table available in the database but not yet present in the + ``MetaData``. May be called multiple times to pick up tables recently + added to the database, however no special action is taken if a table + in this ``MetaData`` no longer exists in the database. + + :param bind: + A :class:`.Connectable` used to access the database; if None, uses + the existing bind on this ``MetaData``, if any. + + :param schema: + Optional, query and reflect tables from an alterate schema. + If None, the schema associated with this :class:`.MetaData` + is used, if any. + + :param views: + If True, also reflect views. + + :param only: + Optional. Load only a sub-set of available named tables. May be + specified as a sequence of names or a callable. + + If a sequence of names is provided, only those tables will be + reflected. An error is raised if a table is requested but not + available. Named tables already present in this ``MetaData`` are + ignored. + + If a callable is provided, it will be used as a boolean predicate to + filter the list of potential table names. The callable is called + with a table name and this ``MetaData`` instance as positional + arguments and should return a true value for any table to reflect. + + """ + if bind is None: + bind = _bind_or_error(self) + + with bind.connect() as conn: + + reflect_opts = { + 'autoload': True, + 'autoload_with': conn + } + + if schema is None: + schema = self.schema + + if schema is not None: + reflect_opts['schema'] = schema + + available = util.OrderedSet(bind.engine.table_names(schema, + connection=conn)) + if views: + available.update( + bind.dialect.get_view_names(conn, schema) + ) + + if schema is not None: + available_w_schema = util.OrderedSet(["%s.%s" % (schema, name) + for name in available]) + else: + available_w_schema = available + + current = set(self.tables) + + if only is None: + load = [name for name, schname in + zip(available, available_w_schema) + if schname not in current] + elif util.callable(only): + load = [name for name, schname in + zip(available, available_w_schema) + if schname not in current and only(name, self)] + else: + missing = [name for name in only if name not in available] + if missing: + s = schema and (" schema '%s'" % schema) or '' + raise exc.InvalidRequestError( + 'Could not reflect: requested table(s) not available ' + 'in %s%s: (%s)' % + (bind.engine.url, s, ', '.join(missing))) + load = [name for name in only if name not in current] + + for name in load: + Table(name, self, **reflect_opts) + + def append_ddl_listener(self, event_name, listener): + """Append a DDL event listener to this ``MetaData``. + + .. deprecated:: 0.7 + See :class:`.DDLEvents`. + + """ + def adapt_listener(target, connection, **kw): + tables = kw['tables'] + listener(event, target, connection, tables=tables) + + event.listen(self, "" + event_name.replace('-', '_'), adapt_listener) + + def create_all(self, bind=None, tables=None, checkfirst=True): + """Create all tables stored in this metadata. + + Conditional by default, will not attempt to recreate tables already + present in the target database. + + :param bind: + A :class:`.Connectable` used to access the + database; if None, uses the existing bind on this ``MetaData``, if + any. + + :param tables: + Optional list of ``Table`` objects, which is a subset of the total + tables in the ``MetaData`` (others are ignored). + + :param checkfirst: + Defaults to True, don't issue CREATEs for tables already present + in the target database. + + """ + if bind is None: + bind = _bind_or_error(self) + bind._run_visitor(ddl.SchemaGenerator, + self, + checkfirst=checkfirst, + tables=tables) + + def drop_all(self, bind=None, tables=None, checkfirst=True): + """Drop all tables stored in this metadata. + + Conditional by default, will not attempt to drop tables not present in + the target database. + + :param bind: + A :class:`.Connectable` used to access the + database; if None, uses the existing bind on this ``MetaData``, if + any. + + :param tables: + Optional list of ``Table`` objects, which is a subset of the + total tables in the ``MetaData`` (others are ignored). + + :param checkfirst: + Defaults to True, only issue DROPs for tables confirmed to be + present in the target database. + + """ + if bind is None: + bind = _bind_or_error(self) + bind._run_visitor(ddl.SchemaDropper, + self, + checkfirst=checkfirst, + tables=tables) + + +class ThreadLocalMetaData(MetaData): + """A MetaData variant that presents a different ``bind`` in every thread. + + Makes the ``bind`` property of the MetaData a thread-local value, allowing + this collection of tables to be bound to different ``Engine`` + implementations or connections in each thread. + + The ThreadLocalMetaData starts off bound to None in each thread. Binds + must be made explicitly by assigning to the ``bind`` property or using + ``connect()``. You can also re-bind dynamically multiple times per + thread, just like a regular ``MetaData``. + + """ + + __visit_name__ = 'metadata' + + def __init__(self): + """Construct a ThreadLocalMetaData.""" + + self.context = util.threading.local() + self.__engines = {} + super(ThreadLocalMetaData, self).__init__() + + def bind(self): + """The bound Engine or Connection for this thread. + + This property may be assigned an Engine or Connection, or assigned a + string or URL to automatically create a basic Engine for this bind + with ``create_engine()``.""" + + return getattr(self.context, '_engine', None) + + @util.dependencies("sqlalchemy.engine.url") + def _bind_to(self, url, bind): + """Bind to a Connectable in the caller's thread.""" + + if isinstance(bind, util.string_types + (url.URL, )): + try: + self.context._engine = self.__engines[bind] + except KeyError: + e = sqlalchemy.create_engine(bind) + self.__engines[bind] = e + self.context._engine = e + else: + # TODO: this is squirrely. we shouldnt have to hold onto engines + # in a case like this + if bind not in self.__engines: + self.__engines[bind] = bind + self.context._engine = bind + + bind = property(bind, _bind_to) + + def is_bound(self): + """True if there is a bind for this thread.""" + return (hasattr(self.context, '_engine') and + self.context._engine is not None) + + def dispose(self): + """Dispose all bound engines, in all thread contexts.""" + + for e in self.__engines.values(): + if hasattr(e, 'dispose'): + e.dispose() + + + -- cgit v1.2.1 From 4c2863765e34ce27e6383fac8b7d2228ec23285e Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Mon, 12 Aug 2013 17:56:11 -0400 Subject: - header comments --- lib/sqlalchemy/sql/schema.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index dbd7ec03d..183b30077 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -1,4 +1,4 @@ -# sqlalchemy/schema.py +# sql/schema.py # Copyright (C) 2005-2013 the SQLAlchemy authors and contributors # # This module is part of SQLAlchemy and is released under -- cgit v1.2.1 From 59141d360e70d1a762719206e3cb0220b4c53fef Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Wed, 14 Aug 2013 19:58:34 -0400 Subject: - apply an import refactoring to the ORM as well - rework the event system so that event modules load after their targets, dependencies are reversed - create an improved strategy lookup system for the ORM - rework the ORM to have very few import cycles - move out "importlater" to just util.dependency - other tricks to cross-populate modules in as clear a way as possible --- lib/sqlalchemy/sql/schema.py | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index 183b30077..ccab31991 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -31,7 +31,7 @@ as components in SQL expressions. import re import inspect from .. import exc, util, event, inspection -from ..events import SchemaEventTarget +from .base import SchemaEventTarget from . import visitors from . import type_api from .base import _bind_or_error, ColumnCollection @@ -2509,7 +2509,18 @@ class Index(ColumnCollectionMixin, SchemaItem): :param name: The name of the index +<<<<<<< HEAD + :param \*expressions: + Column expressions to include in the index. The expressions + are normally instances of :class:`.Column`, but may also + be arbitrary SQL expressions which ultmately refer to a + :class:`.Column`. + + .. versionadded:: 0.8 :class:`.Index` supports SQL expressions as + well as plain columns. +======= :param \*expressions: Column or SQL expressions. +>>>>>>> master :param unique: Defaults to False: create a unique index. -- cgit v1.2.1 From 869620902a5a9a0cfc8e9021e3aa31178f18152c Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Fri, 16 Aug 2013 10:03:05 -0400 Subject: merge error here, though also hedge between explaining about the expressions here vs. hoping they read the class-level docstring --- lib/sqlalchemy/sql/schema.py | 7 ------- 1 file changed, 7 deletions(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index ccab31991..ce4182c54 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -2509,19 +2509,12 @@ class Index(ColumnCollectionMixin, SchemaItem): :param name: The name of the index -<<<<<<< HEAD :param \*expressions: Column expressions to include in the index. The expressions are normally instances of :class:`.Column`, but may also be arbitrary SQL expressions which ultmately refer to a :class:`.Column`. - .. versionadded:: 0.8 :class:`.Index` supports SQL expressions as - well as plain columns. -======= - :param \*expressions: Column or SQL expressions. ->>>>>>> master - :param unique: Defaults to False: create a unique index. -- cgit v1.2.1 From 2452c49cc4d2244d0efef78e051eb65f79b7c712 Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Sun, 25 Aug 2013 12:28:47 -0400 Subject: added "system=True" to Column, so that we generally don't have to bother with CreateColumn rules --- lib/sqlalchemy/sql/schema.py | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index ce4182c54..5930df124 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -893,6 +893,18 @@ class Column(SchemaItem, ColumnClause): an explicit name, use the :class:`.UniqueConstraint` or :class:`.Index` constructs explicitly. + :param system: When ``True``, indicates this is a "system" column, + that is a column which is automatically made available by the + database, and should not be included in the columns list for a + ``CREATE TABLE`` statement. + + For more elaborate scenarios where columns should be conditionally + rendered differently on different backends, consider custom + compilation rules for :class:`.CreateColumn`. + + ..versionadded:: 0.8.3 Added the ``system=True`` parameter to + :class:`.Column`. + """ name = kwargs.pop('name', None) @@ -922,6 +934,7 @@ class Column(SchemaItem, ColumnClause): self.server_onupdate = kwargs.pop('server_onupdate', None) self.index = kwargs.pop('index', None) self.unique = kwargs.pop('unique', None) + self.system = kwargs.pop('system', False) self.quote = kwargs.pop('quote', None) self.doc = kwargs.pop('doc', None) self.onupdate = kwargs.pop('onupdate', None) -- cgit v1.2.1 From 00f3ca98ce24577f6a7fb40efd15bdb2d86acd26 Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Sun, 25 Aug 2013 12:33:37 -0400 Subject: forgot to add system to the copy() method Conflicts: lib/sqlalchemy/schema.py --- lib/sqlalchemy/sql/schema.py | 1 + 1 file changed, 1 insertion(+) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index 5930df124..ca83236c7 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -1122,6 +1122,7 @@ class Column(SchemaItem, ColumnClause): primary_key=self.primary_key, nullable=self.nullable, unique=self.unique, + system=self.system, quote=self.quote, index=self.index, autoincrement=self.autoincrement, -- cgit v1.2.1 From 031ef0807838842a827135dbace760da7aec215e Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Tue, 27 Aug 2013 20:43:22 -0400 Subject: - A rework to the way that "quoted" identifiers are handled, in that instead of relying upon various ``quote=True`` flags being passed around, these flags are converted into rich string objects with quoting information included at the point at which they are passed to common schema constructs like :class:`.Table`, :class:`.Column`, etc. This solves the issue of various methods that don't correctly honor the "quote" flag such as :meth:`.Engine.has_table` and related methods. The :class:`.quoted_name` object is a string subclass that can also be used explicitly if needed; the object will hold onto the quoting preferences passed and will also bypass the "name normalization" performed by dialects that standardize on uppercase symbols, such as Oracle, Firebird and DB2. The upshot is that the "uppercase" backends can now work with force-quoted names, such as lowercase-quoted names and new reserved words. [ticket:2812] --- lib/sqlalchemy/sql/schema.py | 127 +++++++++++++++++++++++++++++-------------- 1 file changed, 86 insertions(+), 41 deletions(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index ca83236c7..b190c3874 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -37,7 +37,7 @@ from . import type_api from .base import _bind_or_error, ColumnCollection from .elements import ClauseElement, ColumnClause, _truncated_label, \ _as_truncated, TextClause, _literal_as_text,\ - ColumnElement, _find_columns + ColumnElement, _find_columns, quoted_name from .selectable import TableClause import collections import sqlalchemy @@ -67,7 +67,6 @@ class SchemaItem(SchemaEventTarget, visitors.Visitable): """Base class for items that define a database schema.""" __visit_name__ = 'schema_item' - quote = None def _init_items(self, *args): """Initialize the list of child items for this SchemaItem.""" @@ -83,6 +82,17 @@ class SchemaItem(SchemaEventTarget, visitors.Visitable): def __repr__(self): return util.generic_repr(self) + @property + @util.deprecated('0.9', 'Use ``.name.quote``') + def quote(self): + """Return the value of the ``quote`` flag passed + to this schema object, for those schema items which + have a ``name`` field. + + """ + + return self.name.quote + @util.memoized_property def info(self): """Info dictionary associated with the object, allowing user-defined @@ -114,25 +124,29 @@ class Table(SchemaItem, TableClause): a second time will return the *same* :class:`.Table` object - in this way the :class:`.Table` constructor acts as a registry function. - See also: + .. seealso:: - :ref:`metadata_describing` - Introduction to database metadata + :ref:`metadata_describing` - Introduction to database metadata Constructor arguments are as follows: :param name: The name of this table as represented in the database. - This property, along with the *schema*, indicates the *singleton - identity* of this table in relation to its parent :class:`.MetaData`. + The table name, along with the value of the ``schema`` parameter, + forms a key which uniquely identifies this :class:`.Table` within + the owning :class:`.MetaData` collection. Additional calls to :class:`.Table` with the same name, metadata, and schema name will return the same :class:`.Table` object. Names which contain no upper case characters will be treated as case insensitive names, and will not be quoted - unless they are a reserved word. Names with any number of upper - case characters will be quoted and sent exactly. Note that this - behavior applies even for databases which standardize upper - case names as case insensitive such as Oracle. + unless they are a reserved word or contain special characters. + A name with any number of upper case characters is considered + to be case sensitive, and will be sent as quoted. + + To enable unconditional quoting for the table name, specify the flag + ``quote=True`` to the constructor, or use the :class:`.quoted_name` + construct to specify the name. :param metadata: a :class:`.MetaData` object which will contain this table. The metadata is used as a point of association of this table @@ -263,9 +277,17 @@ class Table(SchemaItem, TableClause): :param quote_schema: same as 'quote' but applies to the schema identifier. - :param schema: The *schema name* for this table, which is required if + :param schema: The schema name for this table, which is required if the table resides in a schema other than the default selected schema - for the engine's database connection. Defaults to ``None``. + for the engine's database connection. Defaults to ``None``. + + The quoting rules for the schema name are the same as those for the + ``name`` parameter, in that quoting is applied for reserved words or + case-sensitive names; to enable unconditional quoting for the + schema name, specify the flag + ``quote_schema=True`` to the constructor, or use the :class:`.quoted_name` + construct to specify the name. + :param useexisting: Deprecated. Use extend_existing. @@ -329,6 +351,15 @@ class Table(SchemaItem, TableClause): #metadata._remove_table(name, schema) raise + + @property + @util.deprecated('0.9', 'Use ``table.schema.quote``') + def quote_schema(self): + """Return the value of the ``quote_schema`` flag passed + to this :class:`.Table`.""" + + return self.schema.quote + def __init__(self, *args, **kw): """Constructor for :class:`~.schema.Table`. @@ -341,15 +372,15 @@ class Table(SchemaItem, TableClause): # calling the superclass constructor. def _init(self, name, metadata, *args, **kwargs): - super(Table, self).__init__(name) + super(Table, self).__init__(quoted_name(name, kwargs.pop('quote', None))) self.metadata = metadata + self.schema = kwargs.pop('schema', None) if self.schema is None: self.schema = metadata.schema - self.quote_schema = kwargs.pop( - 'quote_schema', metadata.quote_schema) else: - self.quote_schema = kwargs.pop('quote_schema', None) + quote_schema = kwargs.pop('quote_schema', None) + self.schema = quoted_name(self.schema, quote_schema) self.indexes = set() self.constraints = set() @@ -370,7 +401,7 @@ class Table(SchemaItem, TableClause): include_columns = kwargs.pop('include_columns', None) self.implicit_returning = kwargs.pop('implicit_returning', True) - self.quote = kwargs.pop('quote', None) + if 'info' in kwargs: self.info = kwargs.pop('info') if 'listeners' in kwargs: @@ -444,7 +475,8 @@ class Table(SchemaItem, TableClause): for key in ('quote', 'quote_schema'): if key in kwargs: - setattr(self, key, kwargs.pop(key)) + raise exc.ArgumentError( + "Can't redefine 'quote' or 'quote_schema' arguments") if 'info' in kwargs: self.info = kwargs.pop('info') @@ -597,7 +629,9 @@ class Table(SchemaItem, TableClause): :class:`.Table`, using the given :class:`.Connectable` for connectivity. - See also :meth:`.MetaData.create_all`. + .. seealso:: + + :meth:`.MetaData.create_all`. """ @@ -612,7 +646,9 @@ class Table(SchemaItem, TableClause): :class:`.Table`, using the given :class:`.Connectable` for connectivity. - See also :meth:`.MetaData.drop_all`. + .. seealso:: + + :meth:`.MetaData.drop_all`. """ if bind is None: @@ -925,6 +961,12 @@ class Column(SchemaItem, ColumnClause): "May not pass type_ positionally and as a keyword.") type_ = args.pop(0) + if name is not None: + name = quoted_name(name, kwargs.pop('quote', None)) + elif "quote" in kwargs: + raise exc.ArgumentError("Explicit 'name' is required when " + "sending 'quote' argument") + super(Column, self).__init__(name, type_) self.key = kwargs.pop('key', name) self.primary_key = kwargs.pop('primary_key', False) @@ -935,7 +977,6 @@ class Column(SchemaItem, ColumnClause): self.index = kwargs.pop('index', None) self.unique = kwargs.pop('unique', None) self.system = kwargs.pop('system', False) - self.quote = kwargs.pop('quote', None) self.doc = kwargs.pop('doc', None) self.onupdate = kwargs.pop('onupdate', None) self.autoincrement = kwargs.pop('autoincrement', True) @@ -988,6 +1029,10 @@ class Column(SchemaItem, ColumnClause): raise exc.ArgumentError( "Unknown arguments passed to Column: " + repr(list(kwargs))) +# @property +# def quote(self): +# return getattr(self.name, "quote", None) + def __str__(self): if self.name is None: return "(no name)" @@ -1123,7 +1168,7 @@ class Column(SchemaItem, ColumnClause): nullable=self.nullable, unique=self.unique, system=self.system, - quote=self.quote, + #quote=self.quote, index=self.index, autoincrement=self.autoincrement, default=self.default, @@ -1161,7 +1206,6 @@ class Column(SchemaItem, ColumnClause): key=key if key else name if name else self.key, primary_key=self.primary_key, nullable=self.nullable, - quote=self.quote, _proxies=[self], *fk) except TypeError: util.raise_from_cause( @@ -1791,7 +1835,11 @@ class Sequence(DefaultGenerator): be emitted as well. For platforms that don't support sequences, the :class:`.Sequence` construct is ignored. - See also: :class:`.CreateSequence` :class:`.DropSequence` + .. seealso:: + + :class:`.CreateSequence` + + :class:`.DropSequence` """ @@ -1828,6 +1876,8 @@ class Sequence(DefaultGenerator): forces quoting of the schema name on or off. When left at its default of ``None``, normal quoting rules based on casing and reserved words take place. + :param quote_schema: set the quoting preferences for the ``schema`` + name. :param metadata: optional :class:`.MetaData` object which will be associated with this :class:`.Sequence`. A :class:`.Sequence` that is associated with a :class:`.MetaData` gains access to the @@ -1855,17 +1905,14 @@ class Sequence(DefaultGenerator): """ super(Sequence, self).__init__(for_update=for_update) - self.name = name + self.name = quoted_name(name, quote) self.start = start self.increment = increment self.optional = optional - self.quote = quote if metadata is not None and schema is None and metadata.schema: self.schema = schema = metadata.schema - self.quote_schema = metadata.quote_schema else: - self.schema = schema - self.quote_schema = quote_schema + self.schema = quoted_name(schema, quote_schema) self.metadata = metadata self._key = _get_table_key(name, schema) if metadata: @@ -2556,7 +2603,7 @@ class Index(ColumnCollectionMixin, SchemaItem): # objects are present ColumnCollectionMixin.__init__(self, *columns) - self.name = name + self.name = quoted_name(name, kw.pop("quote", None)) self.unique = kw.pop('unique', False) self.kwargs = kw @@ -2598,7 +2645,9 @@ class Index(ColumnCollectionMixin, SchemaItem): :class:`.Index`, using the given :class:`.Connectable` for connectivity. - See also :meth:`.MetaData.create_all`. + .. seealso:: + + :meth:`.MetaData.create_all`. """ if bind is None: @@ -2611,7 +2660,9 @@ class Index(ColumnCollectionMixin, SchemaItem): :class:`.Index`, using the given :class:`.Connectable` for connectivity. - See also :meth:`.MetaData.drop_all`. + .. seealso:: + + :meth:`.MetaData.drop_all`. """ if bind is None: @@ -2653,12 +2704,9 @@ class MetaData(SchemaItem): MetaData is a thread-safe object after tables have been explicitly defined or loaded via reflection. - See also: - - :ref:`metadata_describing` - Introduction to database metadata + .. seealso:: - .. index:: - single: thread safety; MetaData + :ref:`metadata_describing` - Introduction to database metadata """ @@ -2695,8 +2743,7 @@ class MetaData(SchemaItem): """ self.tables = util.immutabledict() - self.schema = schema - self.quote_schema = quote_schema + self.schema = quoted_name(schema, quote_schema) self._schemas = set() self._sequences = {} self._fk_memos = collections.defaultdict(list) @@ -2742,7 +2789,6 @@ class MetaData(SchemaItem): def __getstate__(self): return {'tables': self.tables, 'schema': self.schema, - 'quote_schema': self.quote_schema, 'schemas': self._schemas, 'sequences': self._sequences, 'fk_memos': self._fk_memos} @@ -2750,7 +2796,6 @@ class MetaData(SchemaItem): def __setstate__(self, state): self.tables = state['tables'] self.schema = state['schema'] - self.quote_schema = state['quote_schema'] self._bind = None self._sequences = state['sequences'] self._schemas = state['schemas'] -- cgit v1.2.1 From 03671e9ee4c13f4d7e98ec4a5076fd9c9979e44d Mon Sep 17 00:00:00 2001 From: Alex Gaynor Date: Wed, 25 Sep 2013 10:29:52 -0700 Subject: Replace a big loop + dict lookup in Connection.execute() with a simple visitor pattern --- lib/sqlalchemy/sql/schema.py | 3 +++ 1 file changed, 3 insertions(+) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index b190c3874..35bab8e9d 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -68,6 +68,9 @@ class SchemaItem(SchemaEventTarget, visitors.Visitable): __visit_name__ = 'schema_item' + def _execute_on_connection(self, connection, multiparams, params): + return connection._execute_default(self, multiparams, params) + def _init_items(self, *args): """Initialize the list of child items for this SchemaItem.""" -- cgit v1.2.1 From f27b7551292fcd0230effc3387b86ac5a544a561 Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Tue, 8 Oct 2013 19:20:09 -0400 Subject: The erroneous kw arg "schema" has been removed from the :class:`.ForeignKey` object. this was an accidental commit that did nothing; a warning is raised in 0.8.3 when this kw arg is used. [ticket:2831] --- lib/sqlalchemy/sql/schema.py | 1 - 1 file changed, 1 deletion(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index 35bab8e9d..92220b0d1 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -1279,7 +1279,6 @@ class ForeignKey(SchemaItem): def __init__(self, column, _constraint=None, use_alter=False, name=None, onupdate=None, ondelete=None, deferrable=None, - schema=None, initially=None, link_to_name=False, match=None): """ Construct a column-level FOREIGN KEY. -- cgit v1.2.1 From 9d38ed33400adf3ba8fdf3af49f26de1270bbe23 Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Fri, 11 Oct 2013 15:55:57 -0400 Subject: The "name" attribute is set on :class:`.Index` before the "attach" events are called, so that attachment events can be used to dynamically generate a name for the index based on the parent table and/or columns. [ticket:2835] --- lib/sqlalchemy/sql/schema.py | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index 92220b0d1..c493b9132 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -2600,14 +2600,15 @@ class Index(ColumnCollectionMixin, SchemaItem): columns.append(expr) self.expressions = expressions + self.name = quoted_name(name, kw.pop("quote", None)) + self.unique = kw.pop('unique', False) + self.kwargs = kw # will call _set_parent() if table-bound column # objects are present ColumnCollectionMixin.__init__(self, *columns) - self.name = quoted_name(name, kw.pop("quote", None)) - self.unique = kw.pop('unique', False) - self.kwargs = kw + def _set_parent(self, table): ColumnCollectionMixin._set_parent(self, table) -- cgit v1.2.1 From 1f1ad557afa4919245c2cb9972099c1504a30a37 Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Fri, 11 Oct 2013 16:16:08 -0400 Subject: The ``default`` argument of :class:`.Column` now accepts a class or object method as an argument, in addition to a standalone function; will properly detect if the "context" argument is accepted or not. --- lib/sqlalchemy/sql/schema.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index c493b9132..fe331ce2e 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -1776,7 +1776,7 @@ class ColumnDefault(DefaultGenerator): on everyone. """ - if inspect.isfunction(fn): + if inspect.isfunction(fn) or inspect.ismethod(fn): inspectable = fn elif inspect.isclass(fn): inspectable = fn.__init__ -- cgit v1.2.1 From 52cfa74e094c32910fa1076375f1ae0c9795d45d Mon Sep 17 00:00:00 2001 From: ijl Date: Sun, 13 Oct 2013 17:13:28 -0400 Subject: #2183: Metadata.reflect() foreign keys include options when the dialect exposes it --- lib/sqlalchemy/sql/schema.py | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index 92220b0d1..3f9ff0067 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -2396,7 +2396,9 @@ class ForeignKeyConstraint(Constraint): ondelete=self.ondelete, use_alter=self.use_alter, link_to_name=self.link_to_name, - match=self.match + match=self.match, + deferrable=self.deferrable, + initially=self.initially ) if table is not None: -- cgit v1.2.1 From 78a38967c4ad94194308f77f60a922236cd75227 Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Mon, 14 Oct 2013 14:53:28 -0400 Subject: The ``.unique`` flag on :class:`.Index` could be produced as ``None`` if it was generated from a :class:`.Column` that didn't specify ``unique`` (where it defaults to ``None``). The flag will now always be ``True`` or ``False``. [ticket:2825] --- lib/sqlalchemy/sql/schema.py | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index fe331ce2e..90c4fb0dd 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -977,8 +977,13 @@ class Column(SchemaItem, ColumnClause): self.default = kwargs.pop('default', None) self.server_default = kwargs.pop('server_default', None) self.server_onupdate = kwargs.pop('server_onupdate', None) + + # these default to None because .index and .unique is *not* + # an informational flag about Column - there can still be an + # Index or UniqueConstraint referring to this Column. self.index = kwargs.pop('index', None) self.unique = kwargs.pop('unique', None) + self.system = kwargs.pop('system', False) self.doc = kwargs.pop('doc', None) self.onupdate = kwargs.pop('onupdate', None) @@ -1126,7 +1131,7 @@ class Column(SchemaItem, ColumnClause): "To create indexes with a specific name, create an " "explicit Index object external to the Table.") Index(_truncated_label('ix_%s' % self._label), - self, unique=self.unique) + self, unique=bool(self.unique)) elif self.unique: if isinstance(self.unique, util.string_types): raise exc.ArgumentError( -- cgit v1.2.1 From 73669c7284548d0e5ab2147f66174c301e732650 Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Fri, 18 Oct 2013 20:01:45 -0400 Subject: - The :meth:`.Table.tometadata` method now produces copies of all :attr:`.SchemaItem.info` dictionaries from all :class:`.SchemaItem` objects within the structure including columns, constraints, foreign keys, etc. As these dictionaries are copies, they are independent of the original dictionary. Previously, only the ``.info`` dictionary of :class:`.Column` was transferred within this operation, and it was only linked in place, not copied. [ticket:2716] --- lib/sqlalchemy/sql/schema.py | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index 90c4fb0dd..40bd5b90a 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -108,6 +108,11 @@ class SchemaItem(SchemaEventTarget, visitors.Visitable): """ return {} + def _schema_item_copy(self, schema_item): + if 'info' in self.__dict__: + schema_item.info = self.info.copy() + schema_item.dispatch._update(self.dispatch) + return schema_item class Table(SchemaItem, TableClause): @@ -718,8 +723,7 @@ class Table(SchemaItem, TableClause): unique=index.unique, *[table.c[col] for col in index.columns.keys()], **index.kwargs) - table.dispatch._update(self.dispatch) - return table + return self._schema_item_copy(table) class Column(SchemaItem, ColumnClause): @@ -1183,12 +1187,10 @@ class Column(SchemaItem, ColumnClause): server_default=self.server_default, onupdate=self.onupdate, server_onupdate=self.server_onupdate, - info=self.info, doc=self.doc, *args ) - c.dispatch._update(self.dispatch) - return c + return self._schema_item_copy(c) def _make_proxy(self, selectable, name=None, key=None, name_is_truncatable=False, **kw): @@ -1384,8 +1386,7 @@ class ForeignKey(SchemaItem): link_to_name=self.link_to_name, match=self.match ) - fk.dispatch._update(self.dispatch) - return fk + return self._schema_item_copy(fk) def _get_colspec(self, schema=None): """Return a string based 'column specification' for this @@ -2228,8 +2229,7 @@ class ColumnCollectionConstraint(ColumnCollectionMixin, Constraint): def copy(self, **kw): c = self.__class__(name=self.name, deferrable=self.deferrable, initially=self.initially, *self.columns.keys()) - c.dispatch._update(self.dispatch) - return c + return self._schema_item_copy(c) def contains_column(self, col): return self.columns.contains_column(col) @@ -2310,8 +2310,7 @@ class CheckConstraint(Constraint): _create_rule=self._create_rule, table=target_table, _autoattach=False) - c.dispatch._update(self.dispatch) - return c + return self._schema_item_copy(c) class ForeignKeyConstraint(Constraint): @@ -2480,8 +2479,11 @@ class ForeignKeyConstraint(Constraint): link_to_name=self.link_to_name, match=self.match ) - fkc.dispatch._update(self.dispatch) - return fkc + for self_fk, other_fk in zip( + self._elements.values(), + fkc._elements.values()): + self_fk._schema_item_copy(other_fk) + return self._schema_item_copy(fkc) class PrimaryKeyConstraint(ColumnCollectionConstraint): -- cgit v1.2.1 From 60a72e7c5635b502c8eb9328f7be2990a321ae59 Mon Sep 17 00:00:00 2001 From: Jacob Magnusson Date: Mon, 28 Oct 2013 23:26:37 +0100 Subject: Super-minor doc fix --- lib/sqlalchemy/sql/schema.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index 6d5ffd4d6..b651aef50 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -901,7 +901,7 @@ class Column(SchemaItem, ColumnClause): A :func:`~sqlalchemy.sql.expression.text` expression will be rendered as-is, without quotes:: - Column('y', DateTime, server_default=text('NOW()'))0 + Column('y', DateTime, server_default=text('NOW()')) y DATETIME DEFAULT NOW() -- cgit v1.2.1 From fe1d64473896b1e8abeb8ddb966447632c057321 Mon Sep 17 00:00:00 2001 From: Vraj Mohan Date: Tue, 12 Nov 2013 18:18:04 -0500 Subject: Fix indentation issues in docstrings --- lib/sqlalchemy/sql/schema.py | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index b651aef50..7bf543a61 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -364,7 +364,8 @@ class Table(SchemaItem, TableClause): @util.deprecated('0.9', 'Use ``table.schema.quote``') def quote_schema(self): """Return the value of the ``quote_schema`` flag passed - to this :class:`.Table`.""" + to this :class:`.Table`. + """ return self.schema.quote -- cgit v1.2.1 From 84af7e6c22100ef26c5a27185b1d270f5afb3370 Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Wed, 11 Dec 2013 19:48:27 -0500 Subject: - The :class:`.ForeignKey` class more aggressively checks the given column argument. If not a string, it checks that the object is at least a :class:`.ColumnClause`, or an object that resolves to one, and that the ``.table`` attribute, if present, refers to a :class:`.TableClause` or subclass, and not something like an :class:`.Alias`. Otherwise, a :class:`.ArgumentError` is raised. [ticket:2883] --- lib/sqlalchemy/sql/schema.py | 55 +++++++++++++++++++++++++++----------------- 1 file changed, 34 insertions(+), 21 deletions(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index 7bf543a61..4d9dc2bda 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -1340,6 +1340,23 @@ class ForeignKey(SchemaItem): """ self._colspec = column + if isinstance(self._colspec, util.string_types): + self._table_column = None + else: + if hasattr(self._colspec, '__clause_element__'): + self._table_column = self._colspec.__clause_element__() + else: + self._table_column = self._colspec + + if not isinstance(self._table_column, ColumnClause): + raise exc.ArgumentError( + "String, Column, or Column-bound argument " + "expected, got %r" % self._table_column) + elif not isinstance(self._table_column.table, (util.NoneType, TableClause)): + raise exc.ArgumentError( + "ForeignKey received Column not bound " + "to a Table, got: %r" % self._table_column.table + ) # the linked ForeignKeyConstraint. # ForeignKey will create this when parent Column @@ -1389,6 +1406,7 @@ class ForeignKey(SchemaItem): ) return self._schema_item_copy(fk) + def _get_colspec(self, schema=None): """Return a string based 'column specification' for this :class:`.ForeignKey`. @@ -1398,16 +1416,25 @@ class ForeignKey(SchemaItem): """ if schema: - return schema + "." + self.column.table.name + \ - "." + self.column.key - elif isinstance(self._colspec, util.string_types): + _schema, tname, colname = self._column_tokens + return "%s.%s.%s" % (schema, tname, colname) + elif self._table_column is not None: + return "%s.%s" % ( + self._table_column.table.fullname, self._table_column.key) + else: return self._colspec - elif hasattr(self._colspec, '__clause_element__'): - _column = self._colspec.__clause_element__() + + + def _table_key(self): + if self._table_column is not None: + if self._table_column.table is None: + return None + else: + return self._table_column.table.key else: - _column = self._colspec + schema, tname, colname = self._column_tokens + return _get_table_key(tname, schema) - return "%s.%s" % (_column.table.fullname, _column.key) target_fullname = property(_get_colspec) @@ -1460,20 +1487,6 @@ class ForeignKey(SchemaItem): schema = None return schema, tname, colname - def _table_key(self): - if isinstance(self._colspec, util.string_types): - schema, tname, colname = self._column_tokens - return _get_table_key(tname, schema) - elif hasattr(self._colspec, '__clause_element__'): - _column = self._colspec.__clause_element__() - else: - _column = self._colspec - - if _column.table is None: - return None - else: - return _column.table.key - def _resolve_col_tokens(self): if self.parent is None: raise exc.InvalidRequestError( -- cgit v1.2.1 From 207aaf2f41cff5970b34999d3cfc845a3b0df29c Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Mon, 16 Dec 2013 19:32:10 -0500 Subject: - for [ticket:2651], leaving CheckConstraint alone, preferring to keep backwards compatibility. A note about backslashing escapes is added. Because the Text() construct now supports bind params better, the example given in the code raises an exception now, so that should cover us. The exception itself has been enhanced to include the key name of the bound param. We're backporting this to 0.8 but 0.8 doesn't have the text->bind behavior that raises. --- lib/sqlalchemy/sql/schema.py | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index 4d9dc2bda..6205ada34 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -2272,7 +2272,11 @@ class CheckConstraint(Constraint): :param sqltext: A string containing the constraint definition, which will be used - verbatim, or a SQL expression construct. + verbatim, or a SQL expression construct. If given as a string, + the object is converted to a :class:`.Text` object. If the textual + string includes a colon character, escape this using a backslash:: + + CheckConstraint(r"foo ~ E'a(?\:b|c)d") :param name: Optional, the in-database name of the constraint. -- cgit v1.2.1 From ecb3865615082301c2e5ab7f8e8a40bfbb99b05c Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Sat, 4 Jan 2014 21:12:31 -0500 Subject: - The :paramref:`.Table.extend_existing` and :paramref:`.Table.autoload_replace` parameters are now available on the :meth:`.MetaData.reflect` method. - starting to use paramref and need newer paramlinks version. --- lib/sqlalchemy/sql/schema.py | 29 +++++++++++++++++++++++------ 1 file changed, 23 insertions(+), 6 deletions(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index 6205ada34..97c160bf5 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -2894,7 +2894,9 @@ class MetaData(SchemaItem): """ return ddl.sort_tables(self.tables.values()) - def reflect(self, bind=None, schema=None, views=False, only=None): + def reflect(self, bind=None, schema=None, views=False, only=None, + extend_existing=False, + autoload_replace=True): """Load all available table definitions from the database. Automatically creates ``Table`` entries in this ``MetaData`` for any @@ -2929,6 +2931,17 @@ class MetaData(SchemaItem): with a table name and this ``MetaData`` instance as positional arguments and should return a true value for any table to reflect. + :param extend_existing: Passed along to each :class:`.Table` as + :paramref:`.Table.extend_existing`. + + .. versionadded:: 0.9.1 + + :param autoload_replace: Passed along to each :class:`.Table` as + :paramref:`.Table.autoload_replace`. + + .. versionadded:: 0.9.1 + + """ if bind is None: bind = _bind_or_error(self) @@ -2937,7 +2950,9 @@ class MetaData(SchemaItem): reflect_opts = { 'autoload': True, - 'autoload_with': conn + 'autoload_with': conn, + 'extend_existing': extend_existing, + 'autoload_replace': autoload_replace } if schema is None: @@ -2963,12 +2978,13 @@ class MetaData(SchemaItem): if only is None: load = [name for name, schname in - zip(available, available_w_schema) - if schname not in current] + zip(available, available_w_schema) + if extend_existing or schname not in current] elif util.callable(only): load = [name for name, schname in zip(available, available_w_schema) - if schname not in current and only(name, self)] + if (extend_existing or schname not in current) + and only(name, self)] else: missing = [name for name in only if name not in available] if missing: @@ -2977,7 +2993,8 @@ class MetaData(SchemaItem): 'Could not reflect: requested table(s) not available ' 'in %s%s: (%s)' % (bind.engine.url, s, ', '.join(missing))) - load = [name for name in only if name not in current] + load = [name for name in only if extend_existing or + name not in current] for name in load: Table(name, self, **reflect_opts) -- cgit v1.2.1 From 8c93a6c7718c2408688eb21a59e008a8dcca8999 Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Sun, 5 Jan 2014 16:42:56 -0500 Subject: - fix some docstring stuff --- lib/sqlalchemy/sql/schema.py | 43 +++++++++++++++++++++++++++++-------------- 1 file changed, 29 insertions(+), 14 deletions(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index 97c160bf5..f8aaac12f 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -522,6 +522,14 @@ class Table(SchemaItem, TableClause): @property def key(self): + """Return the 'key' for this :class:`.Table`. + + This value is used as the dictionary key within the + :attr:`.MetaData.tables` collection. It is typically the same + as that of :attr:`.Table.name` for a table with no :attr:`.Table.schema` + set; otherwise it is typically of the form ``schemaname.tablename``. + + """ return _get_table_key(self.name, self.schema) def __repr__(self): @@ -2719,20 +2727,11 @@ class MetaData(SchemaItem): execution. The :class:`.Table` objects themselves are stored in the - ``metadata.tables`` dictionary. - - The ``bind`` property may be assigned to dynamically. A common pattern is - to start unbound and then bind later when an engine is available:: + :attr:`.MetaData.tables` dictionary. - metadata = MetaData() - # define tables - Table('mytable', metadata, ...) - # connect to an engine later, perhaps after loading a URL from a - # configuration file - metadata.bind = an_engine - - MetaData is a thread-safe object after tables have been explicitly defined - or loaded via reflection. + :class:`.MetaData` is a thread-safe object for read operations. Construction + of new tables within a single :class:`.MetaData` object, either explicitly + or via reflection, may not be completely thread-safe. .. seealso:: @@ -2788,6 +2787,20 @@ class MetaData(SchemaItem): "with reflect=True") self.reflect() + tables = None + """A dictionary of :class:`.Table` objects keyed to their name or "table key". + + The exact key is that determined by the :attr:`.Table.key` attribute; + for a table with no :attr:`.Table.schema` attribute, this is the same + as :attr:`.Table.name`. For a table with a schema, it is typically of the + form ``schemaname.tablename``. + + .. seealso:: + + :attr:`.MetaData.sorted_tables` + + """ + def __repr__(self): return 'MetaData(bind=%r)' % self.bind @@ -2889,7 +2902,9 @@ class MetaData(SchemaItem): .. seealso:: - :meth:`.Inspector.sorted_tables` + :attr:`.MetaData.tables` + + :meth:`.Inspector.get_table_names` """ return ddl.sort_tables(self.tables.values()) -- cgit v1.2.1 From f89d4d216bd7605c920b7b8a10ecde6bfea2238c Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Sun, 5 Jan 2014 16:57:05 -0500 Subject: - happy new year --- lib/sqlalchemy/sql/schema.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index f8aaac12f..6ee92871a 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -1,5 +1,5 @@ # sql/schema.py -# Copyright (C) 2005-2013 the SQLAlchemy authors and contributors +# Copyright (C) 2005-2014 the SQLAlchemy authors and contributors # # This module is part of SQLAlchemy and is released under # the MIT License: http://www.opensource.org/licenses/mit-license.php -- cgit v1.2.1 From 1af8e2491dcbed723d2cdafd44fd37f1a6908e91 Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Sat, 18 Jan 2014 19:26:56 -0500 Subject: - implement kwarg validation and type system for dialect-specific arguments; [ticket:2866] - add dialect specific kwarg functionality to ForeignKeyConstraint, ForeignKey --- lib/sqlalchemy/sql/schema.py | 92 +++++++++++++++++++++++++++----------------- 1 file changed, 57 insertions(+), 35 deletions(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index 6ee92871a..73c2a49c8 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -28,10 +28,9 @@ as components in SQL expressions. """ -import re import inspect from .. import exc, util, event, inspection -from .base import SchemaEventTarget +from .base import SchemaEventTarget, DialectKWArgs from . import visitors from . import type_api from .base import _bind_or_error, ColumnCollection @@ -53,14 +52,6 @@ def _get_table_key(name, schema): return schema + "." + name -def _validate_dialect_kwargs(kwargs, name): - # validate remaining kwargs that they all specify DB prefixes - - for k in kwargs: - m = re.match('^(.+?)_.*', k) - if m is None: - raise TypeError("Additional arguments should be " - "named _, got '%s'" % k) @inspection._self_inspects class SchemaItem(SchemaEventTarget, visitors.Visitable): @@ -115,7 +106,7 @@ class SchemaItem(SchemaEventTarget, visitors.Visitable): return schema_item -class Table(SchemaItem, TableClause): +class Table(DialectKWArgs, SchemaItem, TableClause): """Represent a table in a database. e.g.:: @@ -296,9 +287,13 @@ class Table(SchemaItem, TableClause): ``quote_schema=True`` to the constructor, or use the :class:`.quoted_name` construct to specify the name. - :param useexisting: Deprecated. Use extend_existing. + :param \**kw: Additional keyword arguments not mentioned above are + dialect specific, and passed in the form ``_``. + See the documentation regarding an individual dialect at + :ref:`dialect_toplevel` for detail on documented arguments. + """ __visit_name__ = 'table' @@ -397,7 +392,6 @@ class Table(SchemaItem, TableClause): PrimaryKeyConstraint()._set_parent_with_dispatch(self) self.foreign_keys = set() self._extra_dependencies = set() - self.kwargs = {} if self.schema is not None: self.fullname = "%s.%s" % (self.schema, self.name) else: @@ -502,9 +496,7 @@ class Table(SchemaItem, TableClause): self._init_items(*args) def _extra_kwargs(self, **kwargs): - # validate remaining kwargs that they all specify DB prefixes - _validate_dialect_kwargs(kwargs, "Table") - self.kwargs.update(kwargs) + self._validate_dialect_kwargs(kwargs) def _init_collections(self): pass @@ -1254,7 +1246,7 @@ class Column(SchemaItem, ColumnClause): return ColumnClause.get_children(self, **kwargs) -class ForeignKey(SchemaItem): +class ForeignKey(DialectKWArgs, SchemaItem): """Defines a dependency between two columns. ``ForeignKey`` is specified as an argument to a :class:`.Column` object, @@ -1295,7 +1287,8 @@ class ForeignKey(SchemaItem): def __init__(self, column, _constraint=None, use_alter=False, name=None, onupdate=None, ondelete=None, deferrable=None, - initially=None, link_to_name=False, match=None): + initially=None, link_to_name=False, match=None, + **dialect_kw): """ Construct a column-level FOREIGN KEY. @@ -1345,6 +1338,14 @@ class ForeignKey(SchemaItem): DDL for this constraint. Typical values include SIMPLE, PARTIAL and FULL. + :param \**dialect_kw: Additional keyword arguments are dialect specific, + and passed in the form ``_``. The arguments + are ultimately handled by a corresponding :class:`.ForeignKeyConstraint`. + See the documentation regarding an individual dialect at + :ref:`dialect_toplevel` for detail on documented arguments. + + .. versionadded:: 0.9.2 + """ self._colspec = column @@ -1381,6 +1382,7 @@ class ForeignKey(SchemaItem): self.initially = initially self.link_to_name = link_to_name self.match = match + self._unvalidated_dialect_kw = dialect_kw def __repr__(self): return "ForeignKey(%r)" % self._get_colspec() @@ -1410,7 +1412,8 @@ class ForeignKey(SchemaItem): deferrable=self.deferrable, initially=self.initially, link_to_name=self.link_to_name, - match=self.match + match=self.match, + **self._unvalidated_dialect_kw ) return self._schema_item_copy(fk) @@ -1651,6 +1654,7 @@ class ForeignKey(SchemaItem): onupdate=self.onupdate, ondelete=self.ondelete, deferrable=self.deferrable, initially=self.initially, match=self.match, + **self._unvalidated_dialect_kw ) self.constraint._elements[self.parent] = self self.constraint._set_parent_with_dispatch(table) @@ -2113,14 +2117,14 @@ class PassiveDefault(DefaultClause): DefaultClause.__init__(self, *arg, **kw) -class Constraint(SchemaItem): +class Constraint(DialectKWArgs, SchemaItem): """A table-level SQL constraint.""" __visit_name__ = 'constraint' def __init__(self, name=None, deferrable=None, initially=None, _create_rule=None, - **kw): + **dialect_kw): """Create a SQL constraint. :param name: @@ -2151,9 +2155,10 @@ class Constraint(SchemaItem): _create_rule is used by some types to create constraints. Currently, its call signature is subject to change at any time. - :param \**kwargs: - Dialect-specific keyword parameters, see the documentation - for various dialects and constraints regarding options here. + :param \**dialect_kw: Additional keyword arguments are dialect specific, + and passed in the form ``_``. See the + documentation regarding an individual dialect at :ref:`dialect_toplevel` + for detail on documented arguments. """ @@ -2162,8 +2167,7 @@ class Constraint(SchemaItem): self.initially = initially self._create_rule = _create_rule util.set_creation_order(self) - _validate_dialect_kwargs(kw, self.__class__.__name__) - self.kwargs = kw + self._validate_dialect_kwargs(dialect_kw) @property def table(self): @@ -2237,6 +2241,9 @@ class ColumnCollectionConstraint(ColumnCollectionMixin, Constraint): Optional string. If set, emit INITIALLY when issuing DDL for this constraint. + :param \**kw: other keyword arguments including dialect-specific + arguments are propagated to the :class:`.Constraint` superclass. + """ ColumnCollectionMixin.__init__(self, *columns) Constraint.__init__(self, **kw) @@ -2354,7 +2361,7 @@ class ForeignKeyConstraint(Constraint): def __init__(self, columns, refcolumns, name=None, onupdate=None, ondelete=None, deferrable=None, initially=None, use_alter=False, - link_to_name=False, match=None, table=None): + link_to_name=False, match=None, table=None, **dialect_kw): """Construct a composite-capable FOREIGN KEY. :param columns: A sequence of local column names. The named columns @@ -2399,9 +2406,16 @@ class ForeignKeyConstraint(Constraint): DDL for this constraint. Typical values include SIMPLE, PARTIAL and FULL. + :param \**dialect_kw: Additional keyword arguments are dialect specific, + and passed in the form ``_``. See the + documentation regarding an individual dialect at :ref:`dialect_toplevel` + for detail on documented arguments. + + .. versionadded:: 0.9.2 + """ super(ForeignKeyConstraint, self).\ - __init__(name, deferrable, initially) + __init__(name, deferrable, initially, **dialect_kw) self.onupdate = onupdate self.ondelete = ondelete @@ -2428,7 +2442,8 @@ class ForeignKeyConstraint(Constraint): link_to_name=self.link_to_name, match=self.match, deferrable=self.deferrable, - initially=self.initially + initially=self.initially, + **self.dialect_kwargs ) if table is not None: @@ -2552,7 +2567,7 @@ class UniqueConstraint(ColumnCollectionConstraint): __visit_name__ = 'unique_constraint' -class Index(ColumnCollectionMixin, SchemaItem): +class Index(DialectKWArgs, ColumnCollectionMixin, SchemaItem): """A table-level INDEX. Defines a composite (one or more column) INDEX. @@ -2613,11 +2628,18 @@ class Index(ColumnCollectionMixin, SchemaItem): be arbitrary SQL expressions which ultmately refer to a :class:`.Column`. - :param unique: - Defaults to False: create a unique index. + :param unique=False: + Keyword only argument; if True, create a unique index. + + :param quote=None: + Keyword only argument; whether to apply quoting to the name of + the index. Works in the same manner as that of + :paramref:`.Column.quote`. - :param \**kw: - Other keyword arguments may be interpreted by specific dialects. + :param \**kw: Additional keyword arguments not mentioned above are + dialect specific, and passed in the form ``_``. + See the documentation regarding an individual dialect at + :ref:`dialect_toplevel` for detail on documented arguments. """ self.table = None @@ -2637,7 +2659,7 @@ class Index(ColumnCollectionMixin, SchemaItem): self.expressions = expressions self.name = quoted_name(name, kw.pop("quote", None)) self.unique = kw.pop('unique', False) - self.kwargs = kw + self._validate_dialect_kwargs(kw) # will call _set_parent() if table-bound column # objects are present -- cgit v1.2.1 From 49f1807f8f2acea5494fa77d217dce813a933147 Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Mon, 20 Jan 2014 17:55:01 -0500 Subject: - simplify the mechanics of PrimaryKeyConstraint with regards to reflection; reflection now updates the PKC in place. - support the use case of the empty PrimaryKeyConstraint in order to specify constraint options; the columns marked as primary_key=True will now be gathered into the columns collection, rather than being ignored. [ticket:2910] - add validation such that column specification should only take place in the PrimaryKeyConstraint directly, or by using primary_key=True flags; if both are present, they have to match exactly, otherwise the condition is assumed to be ambiguous, and a warning is emitted; the old behavior of using the PKC columns only is maintained. --- lib/sqlalchemy/sql/schema.py | 118 ++++++++++++++++++++++++++++++++++++++----- 1 file changed, 105 insertions(+), 13 deletions(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index 73c2a49c8..09f52f8a7 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -428,11 +428,6 @@ class Table(DialectKWArgs, SchemaItem, TableClause): def _autoload(self, metadata, autoload_with, include_columns, exclude_columns=()): - if self.primary_key.columns: - PrimaryKeyConstraint(*[ - c for c in self.primary_key.columns - if c.key in exclude_columns - ])._set_parent_with_dispatch(self) if autoload_with: autoload_with.run_callable( @@ -2532,10 +2527,69 @@ class ForeignKeyConstraint(Constraint): class PrimaryKeyConstraint(ColumnCollectionConstraint): """A table-level PRIMARY KEY constraint. - Defines a single column or composite PRIMARY KEY constraint. For a - no-frills primary key, adding ``primary_key=True`` to one or more - ``Column`` definitions is a shorthand equivalent for an unnamed single- or - multiple-column PrimaryKeyConstraint. + The :class:`.PrimaryKeyConstraint` object is present automatically + on any :class:`.Table` object; it is assigned a set of + :class:`.Column` objects corresponding to those marked with + the :paramref:`.Column.primary_key` flag:: + + >>> my_table = Table('mytable', metadata, + ... Column('id', Integer, primary_key=True), + ... Column('version_id', Integer, primary_key=True), + ... Column('data', String(50)) + ... ) + >>> my_table.primary_key + PrimaryKeyConstraint( + Column('id', Integer(), table=, primary_key=True, nullable=False), + Column('version_id', Integer(), table=, primary_key=True, nullable=False) + ) + + The primary key of a :class:`.Table` can also be specified by using + a :class:`.PrimaryKeyConstraint` object explicitly; in this mode of usage, + the "name" of the constraint can also be specified, as well as other + options which may be recognized by dialects:: + + my_table = Table('mytable', metadata, + Column('id', Integer), + Column('version_id', Integer), + Column('data', String(50)), + PrimaryKeyConstraint('id', 'version_id', name='mytable_pk') + ) + + The two styles of column-specification should generally not be mixed. + An warning is emitted if the columns present in the + :class:`.PrimaryKeyConstraint` + don't match the columns that were marked as ``primary_key=True``, if both + are present; in this case, the columns are taken strictly from the + :class:`.PrimaryKeyConstraint` declaration, and those columns otherwise marked + as ``primary_key=True`` are ignored. This behavior is intended to be + backwards compatible with previous behavior. + + .. versionchanged:: 0.9.2 Using a mixture of columns within a + :class:`.PrimaryKeyConstraint` in addition to columns marked as + ``primary_key=True`` now emits a warning if the lists don't match. + The ultimate behavior of ignoring those columns marked with the flag + only is currently maintained for backwards compatibility; this warning + may raise an exception in a future release. + + For the use case where specific options are to be specified on the + :class:`.PrimaryKeyConstraint`, but the usual style of using ``primary_key=True`` + flags is still desirable, an empty :class:`.PrimaryKeyConstraint` may be + specified, which will take on the primary key column collection from + the :class:`.Table` based on the flags:: + + my_table = Table('mytable', metadata, + Column('id', Integer, primary_key=True), + Column('version_id', Integer, primary_key=True), + Column('data', String(50)), + PrimaryKeyConstraint(name='mytable_pk', mssql_clustered=True) + ) + + .. versionadded:: 0.9.2 an empty :class:`.PrimaryKeyConstraint` may now + be specified for the purposes of establishing keyword arguments with the + constraint, independently of the specification of "primary key" columns + within the :class:`.Table` itself; columns marked as ``primary_key=True`` + will be gathered into the empty constraint's column collection. + """ __visit_name__ = 'primary_key_constraint' @@ -2543,13 +2597,51 @@ class PrimaryKeyConstraint(ColumnCollectionConstraint): def _set_parent(self, table): super(PrimaryKeyConstraint, self)._set_parent(table) - if table.primary_key in table.constraints: - table.constraints.remove(table.primary_key) - table.primary_key = self - table.constraints.add(self) + if table.primary_key is not self: + table.constraints.discard(table.primary_key) + table.primary_key = self + table.constraints.add(self) + + table_pks = [c for c in table.c if c.primary_key] + if self.columns and table_pks and \ + set(table_pks) != set(self.columns.values()): + util.warn( + "Table '%s' specifies columns %s as primary_key=True, " + "not matching locally specified columns %s; setting the " + "current primary key columns to %s. This warning " + "may become an exception in a future release" % + ( + table.name, + ", ".join("'%s'" % c.name for c in table_pks), + ", ".join("'%s'" % c.name for c in self.columns), + ", ".join("'%s'" % c.name for c in self.columns) + ) + ) + table_pks[:] = [] for c in self.columns: c.primary_key = True + self.columns.extend(table_pks) + + def _reload(self): + """repopulate this :class:`.PrimaryKeyConstraint` based on the current + columns marked with primary_key=True in the table. + + Also fires a new event. + + This is basically like putting a whole new + :class:`.PrimaryKeyConstraint` object on the parent + :class:`.Table` object without actually replacing the object. + + """ + + # clear out the columns collection; we will re-populate + # based on current primary_key flags + self.columns.clear() + + # fire a new event; this will add all existing + # primary key columns based on the flag. + self._set_parent_with_dispatch(self.table) def _replace(self, col): self.columns.replace(col) -- cgit v1.2.1 From 417aeaf1453c67130fb8f1a2bb21c38e6795ce25 Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Mon, 20 Jan 2014 18:14:02 -0500 Subject: - further refine this so that the ordering of columns is maintained as sent to the primary key constraint; existing tests in the PG dialect confirm this. --- lib/sqlalchemy/sql/schema.py | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) (limited to 'lib/sqlalchemy/sql/schema.py') diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index 09f52f8a7..ba38b5070 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -2623,9 +2623,12 @@ class PrimaryKeyConstraint(ColumnCollectionConstraint): c.primary_key = True self.columns.extend(table_pks) - def _reload(self): - """repopulate this :class:`.PrimaryKeyConstraint` based on the current - columns marked with primary_key=True in the table. + def _reload(self, columns): + """repopulate this :class:`.PrimaryKeyConstraint` given + a set of columns. + + Existing columns in the table that are marked as primary_key=True + are maintained. Also fires a new event. @@ -2633,14 +2636,20 @@ class PrimaryKeyConstraint(ColumnCollectionConstraint): :class:`.PrimaryKeyConstraint` object on the parent :class:`.Table` object without actually replacing the object. + The ordering of the given list of columns is also maintained; these + columns will be appended to the list of columns after any which + are already present. + """ - # clear out the columns collection; we will re-populate - # based on current primary_key flags - self.columns.clear() + # set the primary key flag on new columns. + # note any existing PK cols on the table also have their + # flag still set. + for col in columns: + col.primary_key = True + + self.columns.extend(columns) - # fire a new event; this will add all existing - # primary key columns based on the flag. self._set_parent_with_dispatch(self.table) def _replace(self, col): -- cgit v1.2.1