确保你的connectionstring指向正确的数据库也检查表名是与您使用的相同，即表名不会重命名，而不是您上次使用的。请告诉我是否有帮助。

Make sure that your connectionstring is pointing to the correct database also check the table name is the same as you are using i.e. the table name is not renamed than what you used last time.Let me know if it helps.