select * from order_info where product_name in ('C++', 'Java', 'Python') and status ='completed'and date>'2025-10-15' and user_id in ( select user_id from order_info where product_name in ('C++', 'Java', 'Python') and status ='completed'and date>'2025-10-15' group by user_id having count(user_id)>1) t 这里有t（对子句进行命名）的情况下 报错，如果把t删除掉，又可以正常运行。请问为什么会出现这种情况呢？ 以下是报错时候的系统提示： 执行出错 程序异常退出, 请检查代码"是否有数组越界等异常"或者"是否有语法错误" SQL_ERROR_INFO: "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 't' at line 12"