Question

我想添加代表其他表的月份基数的列。

我有2张桌子。

离开申请

(Float.parseFloat(doc['costprice'].value) - Float.parseFloat(doc['sellingprice'].value) > 0;

留下日期

leaveid     Userid      
1            3
2            4
3            5
4            1

我希望最终根据月份计算总假期数：

dateid    leaveid      leavedates 
1            1          2015-10-06
2            1          2015-10-07 
3            2          2015-11-01
4            2          2015-11-02
5            3          2015-01-01
6            4          2015-02-12

Answer 1

对条目进行条件求和，如下所示： -

SELECT a.userid,
        SUM(IF(MONTH(leavedates) = 1, 1, 0)) AS january,
        SUM(IF(MONTH(leavedates) = 2, 1, 0)) AS february,
        SUM(IF(MONTH(leavedates) = 3, 1, 0)) AS march,
        SUM(IF(MONTH(leavedates) = 4, 1, 0)) AS april,
        SUM(IF(MONTH(leavedates) = 5, 1, 0)) AS may,
        SUM(IF(MONTH(leavedates) = 6, 1, 0)) AS june,
        SUM(IF(MONTH(leavedates) = 7, 1, 0)) AS july,
        SUM(IF(MONTH(leavedates) = 8, 1, 0)) AS august,
        SUM(IF(MONTH(leavedates) = 9, 1, 0)) AS september,
        SUM(IF(MONTH(leavedates) = 10, 1, 0)) AS october,
        SUM(IF(MONTH(leavedates) = 11, 1, 0)) AS november,
        SUM(IF(MONTH(leavedates) = 12, 1, 0)) AS december
FROM Leave_application a
LEFT OUTER JOIN Leave_dates b
ON a.leaveid = b.leaveid
GROUP BY a.userid

Answer 2

执行以下查询： -

SELECT  la.`userid`,
        SUM(IF(MONTH(ld.`leavedates`) = 1, 1, 0)) as january,
        SUM(IF(MONTH(ld.`leavedates`) = 2, 1, 0)) as february,
        SUM(IF(MONTH(ld.`leavedates`) = 3, 1, 0)) as march,
        SUM(IF(MONTH(ld.`leavedates`) = 4, 1, 0)) as april,
        SUM(IF(MONTH(ld.`leavedates`) = 5, 1, 0)) as may,
        SUM(IF(MONTH(ld.`leavedates`) = 6, 1, 0)) as june,
        SUM(IF(MONTH(ld.`leavedates`) = 7, 1, 0)) as july,
        SUM(IF(MONTH(ld.`leavedates`) = 8, 1, 0)) as augest,
        SUM(IF(MONTH(ld.`leavedates`) = 9, 1, 0)) as september,
        SUM(IF(MONTH(ld.`leavedates`) = 10, 1, 0)) as october,
        SUM(IF(MONTH(ld.`leavedates`) = 11, 1, 0)) as november,
        SUM(IF(MONTH(ld.`leavedates`) = 12, 1, 0)) as december
      FROM `leave_application` as la
      LEFT JOIN `leave_dates` as ld
        ON (ld.`leaveid` = la.`leaveid`)
      GROUP BY ld.`leaveid`

MYSQL左两个表的连接月数

2 个答案: