@compiles(schema.DropConstraint, "mysql")
def _mysql_drop_constraint(element, compiler, **kw):

    constraint = element.element
    if isinstance(constraint, (schema.ForeignKeyConstraint,
                                schema.PrimaryKeyConstraint,
                                schema.UniqueConstraint)
                                ):
        return compiler.visit_drop_constraint(element, **kw)
    elif isinstance(constraint, schema.CheckConstraint):
        raise NotImplementedError(
                "MySQL does not support CHECK constraints.")
    else:
        raise NotImplementedError(
                "No generic 'DROP CONSTRAINT' in MySQL - "
                "please specify constraint type")
Add a new route or replace the target for an existing route.
dataset/ETHPy150Open RoseOu/flasky/venv/lib/python2.7/site-packages/alembic/ddl/mysql.py/_mysql_drop_constraint--crossover with--dataset/ETHPy150Open adampresley/bottlepy-bootstrap/app/bottle.py/Router.add