如何在SQL中透视表并设置正确的值

时间:2017-08-14 11:29:28

标签: mysql

我正在尝试通过SQL解决我遇到的一些问题但是目前,没有任何成功,我有一个历史玩家VIP级别表,看起来像这样:

+----------+----------+----------+-------+--+
| PlayerID | OldLevel | NewLevel | Date  |  |
+----------+----------+----------+-------+--+
| 747      | Entry    | Bronze   | 03-17 |  |
| 747      | Bronze   | Silver   | 04-17 |  |
| 123      | Entry    | Bronze   | 03-17 |  |
| 123      | Bronze   | Silver   | 04-17 |  |
| 123      | Silver   | Gold     | 06-17 |  |
+----------+----------+----------+-------+--+

OldVip =播放器VIP级别更改日期(日期列)

之前

NewVIP =玩家VIP级别更改日期(日期列)

我想创建一个将创建以下输出的查询:

+---------+-------+-------+--------+--------+--------+--------+--------+--------+--+
| ID/Date | 01-17 | 02-17 | 03-17  | 04-17  | 05-17  | 06-17  | 07-17  | 08-17  |  |
+---------+-------+-------+--------+--------+--------+--------+--------+--------+--+
| 747     | Entry | Entry | Bronze | Silver | Silver | Silver | Silver | Silver |  |
| 123     | Entry | Entry | Bronze | Silver | Silver | Gold   | Gold   | Gold   |  |
+---------+-------+-------+--------+--------+--------+--------+--------+--------+--+

试图在SELECT语句中使用Cases但没有得到所需的结果。

感谢任何帮助。

0 个答案:

没有答案