From 85317aead6208cd6377167fc7fcc4f57491d97f9 Mon Sep 17 00:00:00 2001 From: Matt Riedemann Date: Wed, 6 Nov 2013 13:04:39 -0800 Subject: Add DB2 10.5 Support This patch adds the initial support for DB2 10.5 to migrate. It includes: 1. The dialect implementation for DB2. 2. The dialect registration with the visitor. 3. Code to parse the engine name in version.py. 4. A new dependency on ibm_db_sa in test-requirements.txt. 5. A connection string in test_db.cfg for ibm_db_sa. Part of blueprint add-db2-support Co-authored-by: Sheng Bo Hou Co-authored-by: Thuy Christenson Co-authored-by: Rahul Priyadarshi Change-Id: I745ec615487b1b06c5d1a09ea316f376d66ee4c0 --- migrate/changeset/databases/__init__.py | 1 + migrate/changeset/databases/ibmdb2.py | 313 ++++++++++++++++++++++++++++++++ migrate/changeset/databases/visitor.py | 4 +- 3 files changed, 317 insertions(+), 1 deletion(-) create mode 100644 migrate/changeset/databases/ibmdb2.py (limited to 'migrate/changeset/databases') diff --git a/migrate/changeset/databases/__init__.py b/migrate/changeset/databases/__init__.py index 8546918..075a787 100644 --- a/migrate/changeset/databases/__init__.py +++ b/migrate/changeset/databases/__init__.py @@ -7,4 +7,5 @@ __all__ = [ 'sqlite', 'mysql', 'oracle', + 'ibmdb2', ] diff --git a/migrate/changeset/databases/ibmdb2.py b/migrate/changeset/databases/ibmdb2.py new file mode 100644 index 0000000..1b995ab --- /dev/null +++ b/migrate/changeset/databases/ibmdb2.py @@ -0,0 +1,313 @@ +""" + DB2 database specific implementations of changeset classes. +""" + +import logging + +from ibm_db_sa import base +from sqlalchemy.schema import (AddConstraint, + CreateIndex, + DropConstraint) +from sqlalchemy.schema import (Index, + PrimaryKeyConstraint, + UniqueConstraint) + +from migrate.changeset import ansisql +from migrate.changeset import constraint +from migrate import exceptions + + +LOG = logging.getLogger(__name__) + +IBMDBSchemaGenerator = base.IBM_DBDDLCompiler + + +def get_server_version_info(dialect): + """Returns the DB2 server major and minor version as a list of ints.""" + return [int(ver_token) for ver_token in dialect.dbms_ver.split('.')[0:2]] + + +def is_unique_constraint_with_null_columns_supported(dialect): + """Checks to see if the DB2 version is at least 10.5. + + This is needed for checking if unique constraints with null columns + are supported. + """ + return get_server_version_info(dialect) >= [10, 5] + + +class IBMDBColumnGenerator(IBMDBSchemaGenerator, + ansisql.ANSIColumnGenerator): + def visit_column(self, column): + nullable = True + if not column.nullable: + nullable = False + column.nullable = True + + table = self.start_alter_table(column) + self.append("ADD COLUMN ") + self.append(self.get_column_specification(column)) + + for cons in column.constraints: + self.traverse_single(cons) + if column.default is not None: + self.traverse_single(column.default) + self.execute() + + #ALTER TABLE STATEMENTS + if not nullable: + self.start_alter_table(column) + self.append("ALTER COLUMN %s SET NOT NULL" % + self.preparer.format_column(column)) + self.execute() + self.append("CALL SYSPROC.ADMIN_CMD('REORG TABLE %s')" % + self.preparer.format_table(table)) + self.execute() + + # add indexes and unique constraints + if column.index_name: + Index(column.index_name, column).create() + elif column.unique_name: + constraint.UniqueConstraint(column, + name=column.unique_name).create() + + # SA bounds FK constraints to table, add manually + for fk in column.foreign_keys: + self.add_foreignkey(fk.constraint) + + # add primary key constraint if needed + if column.primary_key_name: + pk = constraint.PrimaryKeyConstraint( + column, name=column.primary_key_name) + pk.create() + + self.append("COMMIT") + self.execute() + self.append("CALL SYSPROC.ADMIN_CMD('REORG TABLE %s')" % + self.preparer.format_table(table)) + self.execute() + + +class IBMDBColumnDropper(ansisql.ANSIColumnDropper): + def visit_column(self, column): + """Drop a column from its table. + + :param column: the column object + :type column: :class:`sqlalchemy.Column` + """ + #table = self.start_alter_table(column) + super(IBMDBColumnDropper, self).visit_column(column) + self.append("CALL SYSPROC.ADMIN_CMD('REORG TABLE %s')" % + self.preparer.format_table(column.table)) + self.execute() + + +class IBMDBSchemaChanger(IBMDBSchemaGenerator, ansisql.ANSISchemaChanger): + def visit_table(self, table): + """Rename a table; #38. Other ops aren't supported.""" + + self._rename_table(table) + self.append("TO %s" % self.preparer.quote(table.new_name, table.quote)) + self.execute() + self.append("COMMIT") + self.execute() + + def _rename_table(self, table): + self.append("RENAME TABLE %s " % self.preparer.format_table(table)) + + def visit_index(self, index): + old_name = self.preparer.quote(self._index_identifier(index.name), + index.quote) + new_name = self.preparer.quote(self._index_identifier(index.new_name), + index.quote) + self.append("RENAME INDEX %s TO %s" % (old_name, new_name)) + self.execute() + self.append("COMMIT") + self.execute() + + def _run_subvisit(self, delta, func, start_alter=True): + """Runs visit method based on what needs to be changed on column""" + table = delta.table + if start_alter: + self.start_alter_table(table) + ret = func(table, + self.preparer.quote(delta.current_name, delta.quote), + delta) + self.execute() + self._reorg_table(self.preparer.format_table(delta.table)) + + def _reorg_table(self, delta): + self.append("CALL SYSPROC.ADMIN_CMD('REORG TABLE %s')" % delta) + self.execute() + + def visit_column(self, delta): + keys = delta.keys() + tr = self.connection.begin() + column = delta.result_column.copy() + + if 'type' in keys: + try: + self._run_subvisit(delta, self._visit_column_change, False) + except Exception as e: + LOG.warn("Unable to change the column type. Error: %s" % e) + + if column.primary_key and 'primary_key' not in keys: + try: + self._run_subvisit(delta, self._visit_primary_key) + except Exception as e: + LOG.warn("Unable to add primary key. Error: %s" % e) + + if 'nullable' in keys: + self._run_subvisit(delta, self._visit_column_nullable) + + if 'server_default' in keys: + self._run_subvisit(delta, self._visit_column_default) + + if 'primary_key' in keys: + self._run_subvisit(delta, self._visit_primary_key) + self._run_subvisit(delta, self._visit_unique_constraint) + + if 'name' in keys: + try: + self._run_subvisit(delta, self._visit_column_name, False) + except Exception as e: + LOG.warn("Unable to change column %(name)s. Error: %(error)s" % + {'name': delta.current_name, 'error': e}) + + self._reorg_table(self.preparer.format_table(delta.table)) + self.append("COMMIT") + self.execute() + tr.commit() + + def _visit_unique_constraint(self, table, col_name, delta): + # Add primary key to the current column + self.append("ADD CONSTRAINT %s " % col_name) + self.append("UNIQUE (%s)" % col_name) + + def _visit_primary_key(self, table, col_name, delta): + # Add primary key to the current column + self.append("ADD PRIMARY KEY (%s)" % col_name) + + def _visit_column_name(self, table, col_name, delta): + column = delta.result_column.copy() + + # Delete the primary key before renaming the column + if column.primary_key: + try: + self.start_alter_table(table) + self.append("DROP PRIMARY KEY") + self.execute() + except Exception: + LOG.debug("Continue since Primary key does not exist.") + + self.start_alter_table(table) + new_name = self.preparer.format_column(delta.result_column) + self.append("RENAME COLUMN %s TO %s" % (col_name, new_name)) + + if column.primary_key: + # execute the rename before adding primary key back + self.execute() + self.start_alter_table(table) + self.append("ADD PRIMARY KEY (%s)" % new_name) + + def _visit_column_nullable(self, table, col_name, delta): + self.append("ALTER COLUMN %s " % col_name) + nullable = delta['nullable'] + if nullable: + self.append("DROP NOT NULL") + else: + self.append("SET NOT NULL") + + def _visit_column_default(self, table, col_name, delta): + default_text = self.get_column_default_string(delta.result_column) + self.append("ALTER COLUMN %s " % col_name) + if default_text is None: + self.append("DROP DEFAULT") + else: + self.append("SET WITH DEFAULT %s" % default_text) + + def _visit_column_change(self, table, col_name, delta): + column = delta.result_column.copy() + + # Delete the primary key before + if column.primary_key: + try: + self.start_alter_table(table) + self.append("DROP PRIMARY KEY") + self.execute() + except Exception: + LOG.debug("Continue since Primary key does not exist.") + # Delete the identity before + try: + self.start_alter_table(table) + self.append("ALTER COLUMN %s DROP IDENTITY" % col_name) + self.execute() + except Exception: + LOG.debug("Continue since identity does not exist.") + + column.default = None + if not column.table: + column.table = delta.table + self.start_alter_table(table) + self.append("ALTER COLUMN %s " % col_name) + self.append("SET DATA TYPE ") + type_text = self.dialect.type_compiler.process( + delta.result_column.type) + self.append(type_text) + + +class IBMDBConstraintGenerator(ansisql.ANSIConstraintGenerator): + def _visit_constraint(self, constraint): + constraint.name = self.get_constraint_name(constraint) + if (isinstance(constraint, UniqueConstraint) and + is_unique_constraint_with_null_columns_supported( + self.dialect)): + for column in constraint.columns._all_cols: + if column.nullable: + constraint.exclude_nulls = True + break + if getattr(constraint, 'exclude_nulls', None): + index = Index(constraint.name, + *(column for column in constraint.columns._all_cols), + unique=True) + sql = self.process(CreateIndex(index)) + sql += ' EXCLUDE NULL KEYS' + else: + sql = self.process(AddConstraint(constraint)) + self.append(sql) + self.execute() + + +class IBMDBConstraintDropper(ansisql.ANSIConstraintDropper, + ansisql.ANSIConstraintCommon): + def _visit_constraint(self, constraint): + constraint.name = self.get_constraint_name(constraint) + if (isinstance(constraint, UniqueConstraint) and + is_unique_constraint_with_null_columns_supported( + self.dialect)): + for column in constraint.columns._all_cols: + if column.nullable: + constraint.exclude_nulls = True + break + if getattr(constraint, 'exclude_nulls', None): + index_name = self.preparer.quote( + self._index_identifier(constraint.name), constraint.quote) + sql = 'DROP INDEX %s ' % index_name + else: + sql = self.process(DropConstraint(constraint, + cascade=constraint.cascade)) + self.append(sql) + self.execute() + + def visit_migrate_primary_key_constraint(self, constraint): + self.start_alter_table(constraint.table) + self.append("DROP PRIMARY KEY") + self.execute() + + +class IBMDBDialect(ansisql.ANSIDialect): + columngenerator = IBMDBColumnGenerator + columndropper = IBMDBColumnDropper + schemachanger = IBMDBSchemaChanger + constraintgenerator = IBMDBConstraintGenerator + constraintdropper = IBMDBConstraintDropper diff --git a/migrate/changeset/databases/visitor.py b/migrate/changeset/databases/visitor.py index 228b4d3..224c40f 100644 --- a/migrate/changeset/databases/visitor.py +++ b/migrate/changeset/databases/visitor.py @@ -8,7 +8,8 @@ from migrate.changeset.databases import (sqlite, postgres, mysql, oracle, - firebird) + firebird, + ibmdb2) # Map SA dialects to the corresponding Migrate extensions @@ -20,6 +21,7 @@ DIALECTS = { "mysql": mysql.MySQLDialect, "oracle": oracle.OracleDialect, "firebird": firebird.FBDialect, + "ibm_db_sa": ibmdb2.IBMDBDialect } -- cgit v1.2.1