Question

我有一个状态历史记录表，其中还包含未来的日期记录。

示例：employee_jobs

[a-z]

我需要一个预先形成的SQL，它会在给定日期时显示给定的employee_id的当前实时记录：示例日期= 2016-08-15

结果集应为：

id | employee_id | division_id | department_id | job_id | effective_date
1     100          1             1               1        2015-01-01
2     100          1             1               2        2016-01-01
3     100          1             2               4        2017-01-01
4     200          1             3               5        2016-01-01
5     300          1             3               6        2015-01-01
6     300          1             3               7        2016-05-25

Answer 1

我想您希望每个员工拥有约束的最新effective_date的记录

（effective_date必须小于或等于给定日期）

SELECT 
*
FROM 
(
    SELECT 
    *,
    IF(@sameEmployee = employee_id, @rn := @rn + 1,
         IF(@sameEmployee := employee_id, @rn := 1, @rn := 1)
     ) AS row_number
    FROM employee_jobs
    CROSS JOIN (SELECT @sameEmployee := 0, @rn := 1) var
    WHERE effective_date <= '2016-08-15'
    ORDER BY employee_id, effective_date DESC
) AS t
WHERE t.row_number = 1
ORDER BY t.employee_id

获取超过指定日期的每位员工的最新记录

1 个答案: