diff options
Diffstat (limited to 'lib/sqlalchemy/schema.py')
| -rw-r--r-- | lib/sqlalchemy/schema.py | 70 |
1 files changed, 49 insertions, 21 deletions
diff --git a/lib/sqlalchemy/schema.py b/lib/sqlalchemy/schema.py index 83f282b24..3a2ff97a7 100644 --- a/lib/sqlalchemy/schema.py +++ b/lib/sqlalchemy/schema.py @@ -93,13 +93,14 @@ class _TableSingleton(expression._FigureVisitName): key = _get_table_key(name, schema) try: table = metadata.tables[key] - if args: - if not useexisting: - raise exceptions.ArgumentError("Table '%s' is already defined for this MetaData instance." % key) + if not useexisting and table._cant_override(*args, **kwargs): + raise exceptions.InvalidRequestError("Table '%s' is already defined for this MetaData instance. Specify 'useexisting=True' to redefine options and columns on an existing Table object." % key) + else: + table._init_existing(*args, **kwargs) return table except KeyError: if mustexist: - raise exceptions.ArgumentError("Table '%s' not defined" % (key)) + raise exceptions.InvalidRequestError("Table '%s' not defined" % (key)) try: return type.__call__(self, name, metadata, *args, **kwargs) except: @@ -201,26 +202,16 @@ class Table(SchemaItem, expression.TableClause): self.primary_key = PrimaryKeyConstraint() self._foreign_keys = util.OrderedSet() self.ddl_listeners = util.defaultdict(list) - self.quote = kwargs.pop('quote', False) - self.quote_schema = kwargs.pop('quote_schema', False) + self.kwargs = {} if self.schema is not None: self.fullname = "%s.%s" % (self.schema, self.name) else: self.fullname = self.name - self.owner = kwargs.pop('owner', None) - if kwargs.get('info'): - self._info = kwargs.pop('info') autoload = kwargs.pop('autoload', False) autoload_with = kwargs.pop('autoload_with', None) include_columns = kwargs.pop('include_columns', None) - # validate remaining kwargs that they all specify DB prefixes - if len([k for k in kwargs if not re.match(r'^(?:%s)_' % '|'.join(databases.__all__), k)]): - raise TypeError("Invalid argument(s) for Table: %s" % repr(kwargs.keys())) - - self.kwargs = kwargs - self._set_parent(metadata) # load column definitions from the database if 'autoload' is defined # we do it after the table is in the singleton dictionary to support @@ -233,8 +224,44 @@ class Table(SchemaItem, expression.TableClause): # initialize all the column, etc. objects. done after # reflection to allow user-overrides - self._init_items(*args) + self.__post_init(*args, **kwargs) + + def _init_existing(self, *args, **kwargs): + autoload = kwargs.pop('autoload', False) + autoload_with = kwargs.pop('autoload_with', None) + schema = kwargs.pop('schema', None) + if schema and schema != self.schema: + raise exceptions.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: + for c in self.c: + if c.name not in include_columns: + self.c.remove(c) + self.__post_init(*args, **kwargs) + + def _cant_override(self, *args, **kwargs): + """return True if the given arguments cannot be sent to a table that already exists. + + the 'useexisting' flag overrides this. + """ + + return bool(args) or bool(util.Set(kwargs).difference(['autoload', 'autoload_with', 'schema'])) + + def __post_init(self, *args, **kwargs): + self.quote = kwargs.pop('quote', False) + self.quote_schema = kwargs.pop('quote_schema', False) + self.owner = kwargs.pop('owner', None) + if kwargs.get('info'): + self._info = kwargs.pop('info') + # validate remaining kwargs that they all specify DB prefixes + if len([k for k in kwargs if not re.match(r'^(?:%s)_' % '|'.join(databases.__all__), k)]): + raise TypeError("Invalid argument(s) for Table: %s" % repr(kwargs.keys())) + self.kwargs.update(kwargs) + + self._init_items(*args) + def key(self): return _get_table_key(self.name, self.schema) key = property(key) @@ -916,9 +943,10 @@ class ForeignKeyConstraint(Constraint): def _set_parent(self, table): self.table = table - table.constraints.add(self) - for (c, r) in zip(self.__colnames, self.__refcolnames): - self.append_element(c,r) + if self not in table.constraints: + table.constraints.add(self) + for (c, r) in zip(self.__colnames, self.__refcolnames): + self.append_element(c,r) def append_element(self, col, refcol): fk = ForeignKey(refcol, constraint=self, name=self.name, onupdate=self.onupdate, ondelete=self.ondelete, use_alter=self.use_alter) @@ -948,8 +976,8 @@ class PrimaryKeyConstraint(Constraint): def _set_parent(self, table): self.table = table table.primary_key = self - for c in self.__colnames: - self.add(table.c[c]) + for name in self.__colnames: + self.add(table.c[name]) def add(self, col): self.columns.add(col) |