时间戳MySQL查询错误

Question

我希望以下错误是自我解释。我想将event_time与一些cart_time进行比较。我知道，当我们想要这样的操作时，我们需要使用in，但是对于时间戳，比较它

 mysql> SELECT bsid
        FROM access_aug15
        WHERE event_time < (SELECT cart_time 
                            FROM chat_final 
                            WHERE bsid in (SELECT bsid  
                                           FROM access_aug15
                                           WHERE eventid="11"
                                           AND current_page not like  '%cart%'));
 ERROR 1242 (21000): Subquery returns more than 1 row

编辑：表结构Access_aug15

  +-------------------+--------------+------+-----+---------+-------+
  | Field             | Type         | Null | Key | Default | Extra |
  +-------------------+--------------+------+-----+---------+-------+
  | vid               | varchar(200) | YES  |     | NULL    |       |
  | bsid              | varchar(200) | YES  | MUL | NULL    |       |
  | event_time        | datetime     | YES  | MUL | NULL    |       |
  | eventid           | varchar(10)  | YES  | MUL | NULL    |       |
  | current_page      | mediumtext   | YES  |     | NULL    |       |
  | departmentid      | varchar(100) | YES  | MUL | NULL    |       |
  | form_id           | varchar(100) | YES  |     | NULL    |       |
  | form_name         | varchar(100) | YES  |     | NULL    |       |
  | page_title        | varchar(200) | YES  |     | NULL    |       |
  | report_date       | datetime     | YES  | MUL | NULL    |       |
  +-------------------+--------------+------+-----+---------+-------+

table2：chat_final

  +-------------------+--------------+------+-----+---------+-------+
  | Field             | Type         | Null | Key | Default | Extra |
  +-------------------+--------------+------+-----+---------+-------+
  | bsid              | varchar(200) | YES  | MUL | NULL    |       |
  | chat_time         | datetime     | YES  |     | NULL    |       |
  | cart_time         | datetime     | YES  |     | NULL    |       |
  | customerid        | varchar(100) | YES  |     | NULL    |       |
  | detail            | longtext     | YES  |     | NULL    |       |
  | chat_type         | varchar(5)   | YES  |     | NULL    |       |
  +-------------------+--------------+------+-----+---------+-------+

Answer 1

在您的查询子查询中（在另一个查询中查询）应仅返回一个结果..但是它返回多个行。您需要修改子查询。请提供表结构和一些数据...然后我给您正确的查询

Answer 2

select bsid from access_aug15 where event_time <(select cart_time from chat_final 
 where bsid in (select bsid from access_aug15 
 where eventid="11"  and current_page not like  '%cart%' 
 LIMIT 1) 
 LIMIT 1);