from sqlalchemy import MetaData, Table, Column, types

from c2cgeoportal import schema


def upgrade(migrate_engine):
    meta = MetaData(bind=migrate_engine)
    layer = Table('layer', meta, schema=schema, autoload=True)
    Column('queryLayers', types.Unicode).create(layer)


def downgrade(migrate_engine):
    meta = MetaData(bind=migrate_engine)
    layer = Table('layer', meta, schema=schema, autoload=True)
    layer.c.queryLayers.drop()

Add migration script for queryLayers column