从两个表中获取数据以生成事件日历 [英] Get data from two tables to make an event-calendar

问题描述

我有两个表

表用户：

user_id     Name
1          John
2          Alice
3          Tom
4          Charles

表活动：

id         event_id         start_date      end_date        user_id
1            1              2013-03-02      2013-03-03        1
2            2              2013-03-02      2013-03-03        3
3            3              2013-03-04      2013-03-04        1
4            2              2013-03-10      2013-03-15        2

我已经创建了输入部分，并且不能在同一天为同一用户创建两个事件（不重叠）。

I already made the "input" part and is not possible to have two events for the same user in the same day (no overlapping).

我提供月份和年作为变量。

我想有一个mysql查询其结果如下：

I would like to have a mysql query with results like this:

user_id  1  2  3  4  5  6  7  8  9  10  11  12  13  14  15       
  1      0  1  1  3  0  0  0  0  0  0   0   0   0   0   0
  2      0  0  0  0  0  0  0  0  0  2   2   2   2   2   2
  3      0  2  2  0  0  0  0  0  0  0   0   0   0   0   0

谢谢！

推荐答案

UPDATED

SELECT user_id,
       COALESCE(MIN(CASE WHEN  1 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `1`,
       COALESCE(MIN(CASE WHEN  2 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `2`,
       COALESCE(MIN(CASE WHEN  3 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `3`,
       COALESCE(MIN(CASE WHEN  4 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `4`,
       COALESCE(MIN(CASE WHEN  5 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `5`,
       COALESCE(MIN(CASE WHEN  6 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `6`,
       COALESCE(MIN(CASE WHEN  7 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `7`,
       COALESCE(MIN(CASE WHEN  8 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `8`,
       COALESCE(MIN(CASE WHEN  9 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `9`,
       COALESCE(MIN(CASE WHEN 10 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `10`,
       COALESCE(MIN(CASE WHEN 11 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `11`,
       COALESCE(MIN(CASE WHEN 12 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `12`,
       COALESCE(MIN(CASE WHEN 13 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `13`,
       COALESCE(MIN(CASE WHEN 14 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `14`,
       COALESCE(MIN(CASE WHEN 15 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `15`
  FROM 
(
  SELECT id, event_id,
         CASE WHEN start_date < '2013-03-01' THEN '2013-03-01' ELSE start_date END start_date,
         CASE WHEN end_date   > '2013-03-31' THEN '2013-03-31' ELSE   end_date END end_date,
         user_id
    FROM events
   WHERE (start_date >= '2013-03-01' AND end_date <= '2013-03-31')
      OR (start_date <  '2013-03-01' AND end_date  > '2013-03-31')
      OR (start_date  < '2013-03-01' AND end_date BETWEEN '2013-03-01' AND '2013-03-31')
      OR (start_date BETWEEN '2013-03-01' AND '2013-03-31' AND end_date > '2013-03-31') 
) q
 GROUP BY user_id

输出：

| USER_ID | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 |
-----------------------------------------------------------------------------
|       1 | 0 | 1 | 1 | 3 | 0 | 0 | 0 | 0 | 0 |  0 |  0 |  0 |  0 |  0 |  0 |
|       2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |  2 |  2 |  2 |  2 |  2 |  2 |
|       3 | 0 | 2 | 2 | 0 | 0 | 0 | 0 | 0 | 0 |  0 |  0 |  0 |  0 |  0 |  0 |

这是 SQLFiddle 演示

Here is SQLFiddle demo

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