diff options
| -rw-r--r-- | keystone/common/sql/migrate_repo/versions/023_drop_credential_constraints.py | 62 | ||||
| -rw-r--r-- | keystone/common/sql/migration_helpers.py | 58 |
2 files changed, 75 insertions, 45 deletions
diff --git a/keystone/common/sql/migrate_repo/versions/023_drop_credential_constraints.py b/keystone/common/sql/migrate_repo/versions/023_drop_credential_constraints.py index ee1d34eb..8888e651 100644 --- a/keystone/common/sql/migrate_repo/versions/023_drop_credential_constraints.py +++ b/keystone/common/sql/migrate_repo/versions/023_drop_credential_constraints.py @@ -14,64 +14,36 @@ # License for the specific language governing permissions and limitations # under the License. -from migrate import ForeignKeyConstraint import sqlalchemy -from sqlalchemy.orm import sessionmaker -MYSQL_FKEY_QUERY = ("select CONSTRAINT_NAME from " - "INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS " - "where table_name = 'credential'") +from keystone.common.sql import migration_helpers -def drop_constraint_mysql(migrate_engine): - session = sessionmaker(bind=migrate_engine)() - #http://bugs.mysql.com/bug.php?id=10333 - #MySQL varies from the SQL norm in naming - #Foreign Keys. The mapping from the column name - #to the actual foreign key is stored in - #INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS - #SQLAlchemy expects the constraint name to be - # the column name. - for constraint in session.execute(MYSQL_FKEY_QUERY): - session.execute('ALTER TABLE credential DROP FOREIGN KEY %s;' - % constraint[0]) - session.commit() - - -def remove_constraints(migrate_engine): - if migrate_engine.name == 'sqlite': - return - if migrate_engine.name == 'mysql': - drop_constraint_mysql(migrate_engine) - return +def list_constraints(migrate_engine): meta = sqlalchemy.MetaData() meta.bind = migrate_engine user_table = sqlalchemy.Table('user', meta, autoload=True) proj_table = sqlalchemy.Table('project', meta, autoload=True) cred_table = sqlalchemy.Table('credential', meta, autoload=True) - ForeignKeyConstraint(columns=[cred_table.c.user_id], - refcolumns=[user_table.c.id]).drop() - ForeignKeyConstraint(columns=[cred_table.c.project_id], - refcolumns=[proj_table.c.id]).drop() - -def add_constraints(migrate_engine): - if migrate_engine.name == 'sqlite': - return - meta = sqlalchemy.MetaData() - meta.bind = migrate_engine - user_table = sqlalchemy.Table('user', meta, autoload=True) - proj_table = sqlalchemy.Table('project', meta, autoload=True) - cred_table = sqlalchemy.Table('credential', meta, autoload=True) - ForeignKeyConstraint(columns=[cred_table.c.user_id], - refcolumns=[user_table.c.id]).create() - ForeignKeyConstraint(columns=[cred_table.c.project_id], - refcolumns=[proj_table.c.id]).create() + constraints = [{'table': cred_table, + 'fk_column': 'user_id', + 'ref_column': user_table.c.id}, + {'table': cred_table, + 'fk_column': 'project_id', + 'ref_column': proj_table.c.id}] + return constraints def upgrade(migrate_engine): - remove_constraints(migrate_engine) + # SQLite does not support constraints, and querying the constraints + # raises an exception + if migrate_engine.name == 'sqlite': + return + migration_helpers.remove_constraints(list_constraints(migrate_engine)) def downgrade(migrate_engine): - add_constraints(migrate_engine) + if migrate_engine.name == 'sqlite': + return + migration_helpers.add_constraints(list_constraints(migrate_engine)) diff --git a/keystone/common/sql/migration_helpers.py b/keystone/common/sql/migration_helpers.py new file mode 100644 index 00000000..6d735f5e --- /dev/null +++ b/keystone/common/sql/migration_helpers.py @@ -0,0 +1,58 @@ +# vim: tabstop=4 shiftwidth=4 softtabstop=4 + +# Copyright 2013 OpenStack LLC +# Copyright 2013 Red Hat, Inc. +# All Rights Reserved. +# +# Licensed under the Apache License, Version 2.0 (the "License"); you may +# not use this file except in compliance with the License. You may obtain +# a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT +# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the +# License for the specific language governing permissions and limitations +# under the License. +import migrate +import sqlalchemy + + +# Different RDBMSs use different schemes for naming the Foreign Key +# Constraints. SQLAlchemy does not yet attempt to determine the name +# for the constraint, and instead attempts to deduce it from the column. +# This fails on MySQL. +def get_fkey_constraint_name(table, column_name): + fkeys = [fk for fk in table.constraints + if (column_name in fk.columns and + isinstance(fk, sqlalchemy.ForeignKeyConstraint))] + constraint_name = fkeys[0].name + return constraint_name + + +# remove_constraints and add_constraints both accept a list of dictionaries +# that contain: +# {'table': a sqlalchemy table. The constraint is added to to dropped from +# this table. +# 'fk_column': the name of a column on the above table, The constraint +# is added to or dropped from this column +# 'ref_column':a sqlalchemy column object. This is the reference column +# for the constraint. +def remove_constraints(constraints): + for constraint_def in constraints: + migrate.ForeignKeyConstraint( + columns=[getattr(constraint_def['table'].c, + constraint_def['fk_column'])], + refcolumns=[constraint_def['ref_column']], + name=(get_fkey_constraint_name + (constraint_def['table'], + constraint_def['fk_column']))).drop() + + +def add_constraints(constraints): + for constraint_def in constraints: + migrate.ForeignKeyConstraint( + columns=[getattr(constraint_def['table'].c, + constraint_def['fk_column'])], + refcolumns=[constraint_def['ref_column']]).create() |