def handle(self, *args, **kwargs):
"""Will search in all installed models to find which ones define
a constraint. No constraint is modified until all are valid.
In case a constrait name is already used, will raise and
exception
"""
cursor = connection.cursor()
for model in models.get_models(include_auto_created=True):
if getattr(model._meta, 'constraints', []):
check_names = []
sql_for_constraints = []
for check in model._meta.constraints:
check_name, check_obj = check
if not check_name in check_names:
check_names.append(check_name)
check_obj.check_name = check_name
alter_sql = u'ALTER TABLE {0}'.format(model._meta.db_table)
drop_sql = u'{0} DROP CONSTRAINT IF EXISTS {1}'.format(
alter_sql, check_name)
cursor.execute(drop_sql)
add_sql = u'{0} ADD {1}'.format(
alter_sql, check_obj.generate_sql(connection, style()))
self.stdout.write('\033[01;32mAdding constraint: \033[m{0}'.format(
add_sql))
sql_for_constraints.append(';'.join([
drop_sql, u'{0} ADD {1}'.format(
alter_sql, check_obj.generate_sql(connection, style))]))
else:
raise Exception(
u'\033[01;31m{0} already defined in {1}'.format(
check_name, model.__class__))
cursor.execute(';'.join(sql_for_constraints))
self.stdout.write('\n\033[01;32mConstraints installed!')
def getSQL(model):
creation = connections[model.__database__].creation
return creation.sql_create_model(model, style())[0]