ALTER TABLE yourtable DROP CONSTRAINT DF_AspNetUser_UserN__34C8D9D1

ALTER TABLE TableName DROP CONSTRAINT dependent_constraint;

ioc.For<IIdentity>().Use(() => HttpContext.Current.User.Identity);
ioc.For<HttpContextBase>().Use(() => new HttpContextWrapper(HttpContext.Current));
ioc.For<HttpServerUtilityBase>().Use(() => new HttpServerUtilityWrapper(HttpContext.Current.Server));
ioc.For<HttpRequestBase>().Use(ctx => ctx.GetInstance<HttpContextBase>().Request);