def reverse(apps, schema_editor):
"""
Drop the new geo_version column from all data tables
"""
session = get_session()
inspector = inspect(session.bind)
try:
for data_table in DATA_TABLES.values():
db_model = data_table.model
table = db_model.__table__
# remove the primary key constraint, if any
pk = inspector.get_pk_constraint(table.name)['name']
if pk:
session.execute("ALTER TABLE %s DROP CONSTRAINT %s" %
(table.name, pk))
# drop the new column
session.execute("ALTER TABLE %s DROP COLUMN geo_version" %
table.name)
# add the old pk constraint
pk = table.primary_key
pk.columns.remove(table.c.geo_version)
session.execute(AddConstraint(pk))
session.commit()
finally:
session.close()
def forwards(apps, schema_editor):
"""
Ensure all data tables have the new geo_version column, with a default of ''
"""
session = get_session()
inspector = inspect(session.bind)
try:
for data_table in DATA_TABLES.values():
db_model = data_table.model
table = db_model.__table__
cols = [c['name'] for c in inspector.get_columns(table.name)]
if 'geo_version' in cols:
continue
# remove the old primary key constraint, if any
pk = inspector.get_pk_constraint(table.name)['name']
if pk:
session.execute("ALTER TABLE %s DROP CONSTRAINT %s" %
(table.name, pk))
# add the new column
session.execute(
"ALTER TABLE %s ADD COLUMN geo_version VARCHAR(100) DEFAULT ''"
% table.name)
# add the correct new constraint
session.execute(AddConstraint(table.primary_key))
session.commit()
finally:
session.close()