text: # Copyright (c) 2012 Red Hat, Inc.
  #
  #    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 sqlalchemy import Column, MetaData, String, Table
  
  
  def upgrade(migrate_engine):
      meta = MetaData()
      meta.bind = migrate_engine
      token = Table('token', meta, autoload=True)
      old_id_col = token.c.id
      old_id_col.alter(name='id_hash')
      # Note: We obtain a new metadata reference to avoid
      # sqlalchemy.exc.ArgumentError:
      # Trying to redefine primary-key column 'id' as a non-primary-key...
      meta = MetaData()
      meta.bind = migrate_engine
      token = Table('token', meta, autoload=True)
      new_id = Column("id", String(2048))
      token.create_column(new_id)
  
  
  def downgrade(migrate_engine):
      meta = MetaData()
      meta.bind = migrate_engine
      token = Table('token', meta, autoload=True)
      token.drop_column('id')
      token = Table('token', meta, autoload=True)
      id_col = token.c.id_hash
      id_col.alter(name='id')
  