diff options
Diffstat (limited to 'neutron/db/migration/__init__.py')
| -rw-r--r-- | neutron/db/migration/__init__.py | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/neutron/db/migration/__init__.py b/neutron/db/migration/__init__.py index 55c1443f1f..86cce385af 100644 --- a/neutron/db/migration/__init__.py +++ b/neutron/db/migration/__init__.py @@ -12,11 +12,13 @@ # License for the specific language governing permissions and limitations # under the License. +import contextlib import functools from alembic import context from alembic import op import sqlalchemy as sa +from sqlalchemy.engine import reflection def skip_if_offline(func): @@ -122,3 +124,35 @@ def create_table_if_not_exist_psql(table_name, values): "WHERE NOT table_exist(%(name)r);" % {'name': table_name, 'columns': values}) + + +def remove_foreign_keys(table, foreign_keys): + for fk in foreign_keys: + op.drop_constraint( + name=fk['name'], + table_name=table, + type_='foreignkey' + ) + + +def create_foreign_keys(table, foreign_keys): + for fk in foreign_keys: + op.create_foreign_key( + name=fk['name'], + source=table, + referent=fk['referred_table'], + local_cols=fk['constrained_columns'], + remote_cols=fk['referred_columns'], + ondelete='CASCADE' + ) + + +@contextlib.contextmanager +def remove_fks_from_table(table): + try: + inspector = reflection.Inspector.from_engine(op.get_bind()) + foreign_keys = inspector.get_foreign_keys(table) + remove_foreign_keys(table, foreign_keys) + yield + finally: + create_foreign_keys(table, foreign_keys) |