text: # vim: tabstop=4 shiftwidth=4 softtabstop=4
  
  # Copyright 2014 Intel 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.
  
  from sqlalchemy import Boolean, Column, DateTime, ForeignKey
  from sqlalchemy import Integer, MetaData, String, Table
  from vsm.db.sqlalchemy import models
  
  def upgrade(migrate_engine):
      # Upgrade operations go here. Don't create your own engine;
      # bind migrate_engine to your metadata
      meta = MetaData()
      meta.bind = migrate_engine
  
      storage_pool_usages = Table(
          'storage_pool_usages', meta,
          Column('id', Integer, primary_key=True, nullable=False),
          Column('pool_id', Integer, ForeignKey(models.StoragePool.id), nullable=False),
          Column('vsmapp_id', Integer, ForeignKey(models.Vsmapp.id), nullable=False),
          Column('attach_status', String(length=255), nullable=False),
          Column('attach_at', DateTime(timezone=False)),
          Column('terminate_at', DateTime(timezone=False)),
          Column('created_at', DateTime(timezone=False)),
          Column('updated_at', DateTime(timezone=False)),
          Column('deleted_at', DateTime(timezone=False)),
          Column('deleted', Boolean(create_constraint=True, name=None), default=False),
      )
  
      try:
          storage_pool_usages.create()
      except Exception:
          meta.drop_all(tables=[storage_pool_usages])
          raise
  
  def downgrade(migrate_engine):
      meta = MetaData()
      meta.bind = migrate_engine
      table = Table('storage_pool_usages',
                          meta,
                          autoload=True)
      table.drop()
  
  