tacker/tacker/db/migration/__init__.py

38 lines
1.6 KiB
Python

# Copyright 2012 New Dream Network, LLC (DreamHost)
#
# 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.
from alembic import op
import sqlalchemy as sa
def alter_enum(table, column, enum_type, nullable):
bind = op.get_bind()
engine = bind.engine
if engine.name == 'postgresql':
values = {'table': table,
'column': column,
'name': enum_type.name}
op.execute("ALTER TYPE %(name)s RENAME TO old_%(name)s" % values)
enum_type.create(bind, checkfirst=False)
op.execute("ALTER TABLE %(table)s RENAME COLUMN %(column)s TO "
"old_%(column)s" % values)
op.add_column(table, sa.Column(column, enum_type, nullable=nullable))
op.execute("UPDATE %(table)s SET %(column)s = "
"old_%(column)s::text::%(name)s" % values)
op.execute("ALTER TABLE %(table)s DROP COLUMN old_%(column)s" % values)
op.execute("DROP TYPE old_%(name)s" % values)
else:
op.alter_column(table, column, type_=enum_type,
existing_nullable=nullable)