fix for this

gistfile1.py

from flask.ext.sqlalchemy import SQLAlchemy
from sqlalchemy.interfaces import PoolListener


class SQLiteForeignKeysListener(PoolListener):
    def connect(self, dbapi_con, con_record):
        db_cursor = dbapi_con.execute('pragma foreign_keys=ON')


class StrictSQLAlchemy(SQLAlchemy):
    def apply_driver_hacks(self, app, info, options):
        super(StrictSQLAlchemy, self).apply_driver_hacks(app, info, options)
        if info.drivername == 'sqlite':
            options.setdefault('listeners', []).append(SQLiteForeignKeysListener())

db = StrictSQLAlchemy(app)