text: """add_aichip_type
  
  Revision ID: 589ff20545b7
  Revises: ede4e3f1a232
  Create Date: 2019-05-22 06:01:08.292535
  
  """
  
  # revision identifiers, used by Alembic.
  revision = '589ff20545b7'
  down_revision = 'ede4e3f1a232'
  
  from alembic import op
  import sqlalchemy as sa
  
  
  def upgrade():
      new_device_type = sa.Enum('GPU', 'FPGA', 'AICHIP',
                                name='device_type')
      op.alter_column('devices', 'type',
                      existing_type=new_device_type,
                      nullable=False)
  