Question

我在构建查询时遇到问题，以获取同一个表中时间字段的两个总和的值。

理想情况下，我希望在日期范围内选择总值，但也可以在MySQL子句中应用日期范围之前得到总数。

我使用子查询构建了下面的内容，但这很慢，并且在8.5秒内完成！

反正有加速吗？

SELECT u.user_id,
       u.forename,
       u.surname,
       c.client_name,
       p.project_name,
       SUM(t.time_taken) AS total_project_time_between_dates,
       (SELECT SUM(st.time_taken) 
        FROM tbl_mt_tasks st 
        WHERE st.user_id = u.user_id 
          AND st.project_id = p.project_id 
        GROUP BY st.user_id, st.project_id, st.client_id  
        LIMIT 1) as total_project_time
FROM tbl_mt_tasks t 
  JOIN tbl_mt_clients c ON t.client_id = c.client_id 
  JOIN tbl_mt_projects p ON t.project_id = p.project_id 
  JOIN tbl_mt_users u ON t.user_id = u.user_id 
WHERE t.date_created  BETWEEN '2015-04-16' AND '2015-04-22' 
  AND u.status != 100 
GROUP BY t.project_id, t.client_id, t.user_id 
ORDER BY  project_name ASC

Answer 1

最后的答案似乎已被删除，但实际上是正确的！要过滤掉结果，我只需要使用HAVING子句！

    SELECT 
        u.user_id,
        u.forename,
        u.surname,
        c.client_name,
        p.project_name,
        SUM(CASE WHEN t.date_created  BETWEEN '2015-04-16' AND '2015-04-22' THEN t.time_taken ELSE 0 END) AS total_project_time_between_dates,
        SUM(time_taken) as total_project_time
    FROM tbl_mt_tasks t 
      JOIN tbl_mt_clients c ON t.client_id = c.client_id 
      JOIN tbl_mt_projects p ON t.project_id = p.project_id 
      JOIN tbl_mt_users u ON t.user_id = u.user_id 
    WHERE u.status != 100 
    GROUP BY 
        u.user_id,
        c.client_id,
        p.project_id 
    HAVING total_project_time_between_dates > 0
    ORDER BY  project_name ASC

选择总计的总和以及带有日期子句的不同总和，不带子查询

1 个答案: