MySQL 子查询从当前查询中的用户 ID 获取不同表中的用户名。如何？

Question

以下查询是迄今为止我能够学习到的最复杂的查询。它从 tbl_user_time_log 计算登录持续时间。

SELECT USER_ID,
       UTL_DTSTAMP,
       UTL_TASK,
       SUM(UTL_DURATION) AS UTL_DURATION_TOTAL       
  FROM (

SELECT A.PK_USER_TIME_LOG_ID,
       A.CLIENT_ID,
       A.PROJECT_ID,
       A.USER_ID,
       A.UTL_DTSTAMP,
       /* DATE_FORMAT(A.UTL_DTSTAMP,'%H:%i:%s') AS UTL_DTSTAMP, */
       A.UTL_LATITUDE,
       A.UTL_LONGITUDE,
       A.UTL_EVENT,
       A.UTL_TASK,
       /* DURATION in seconds  */
       TIMESTAMPDIFF(SECOND, A.UTL_DTSTAMP, B.UTL_DTSTAMP) AS UTL_DURATION
FROM   tbl_user_time_log A
       INNER JOIN tbl_user_time_log B
               ON B.PK_USER_TIME_LOG_ID = ( A.PK_USER_TIME_LOG_ID + 1 )
WHERE  A.USER_ID = '465615'
       /* Between current pay period Start date and Current pay period end date */
       /* First day of the week is Monday.*/

       AND ( A.UTL_DTSTAMP BETWEEN '2019-02-24' AND '2019-03-04' )
       /* Filter out Clock Out. */
       AND A.UTL_EVENT <> 'CLOCK OUT'

  /* Our derived table... */
) AS tbl_derived_1

GROUP BY USER_ID, UTL_TASK;

...返回:

我如何使用相同的查询，但对于它选择的每个用户 ID，显示来自 tbl_user 的相应的用户名字和用户姓氏>?

tbl_user

Answer 1

假设您有一个表 user，其中包含通过 id 与 tbl_user_time_log 相关的名字和姓氏你可以使用连接

SELECT USER_ID,
       u.firstname, 
       u.lastname,
       UTL_DTSTAMP,
       UTL_TASK,
       SUM(UTL_DURATION) AS UTL_DURATION_TOTAL       
  FROM (

SELECT A.PK_USER_TIME_LOG_ID,
       A.CLIENT_ID,
       A.PROJECT_ID,
       A.USER_ID,
       A.UTL_DTSTAMP,
       /* DATE_FORMAT(A.UTL_DTSTAMP,'%H:%i:%s') AS UTL_DTSTAMP, */
       A.UTL_LATITUDE,
       A.UTL_LONGITUDE,
       A.UTL_EVENT,
       A.UTL_TASK,
       /* DURATION in seconds  */
       TIMESTAMPDIFF(SECOND, A.UTL_DTSTAMP, B.UTL_DTSTAMP) AS UTL_DURATION
FROM   tbl_user_time_log A
       INNER JOIN tbl_user_time_log B
               ON B.PK_USER_TIME_LOG_ID = ( A.PK_USER_TIME_LOG_ID + 1 )
WHERE  A.USER_ID = '465615'
       /* Between current pay period Start date and Current pay period end date */
       /* First day of the week is Monday.*/

       AND ( A.UTL_DTSTAMP BETWEEN '2019-02-24' AND '2019-03-04' )
       /* Filter out Clock Out. */
       AND A.UTL_EVENT <> 'CLOCK OUT'

  /* Our derived table... */
) AS tbl_derived_1
INNER JOIN user u ON u.id = tbl_derived_1.USER_ID

GROUP BY USER_ID, UTL_TASK;