将 MySQL 行合并在一起

Question

我有一张这样布置的桌子：

ID  | Date       | Description          | Notes
 1  | 2015-03-25 | Action Completed     | 
 2  | 2015-02-12 | Action Not Completed |
 1  |            |                      | Completed With Ease
 2  |            |                      | Difficulty Performing

是否有任何代码可用于按 ID 将它们合并在一起，像这样？

 ID | Date       | Description          | Notes
 1  | 2015-03-25 | Action Completed     | Completed With Ease
 2  | 2015-02-12 | Action Not Completed | Difficulty Performing

我已经看过了，但找不到任何可以正常工作的东西。

Answer 1

按应该唯一的列分组，然后在其他列上使用聚合函数，例如 max()

select id, 
       max(date) as date, 
       max(description) as description, 
       max(notes) as notes
from your_table
group by id

Answer 2

小提琴：http://sqlfiddle.com/#!9/305b7/1

SELECT id, 
  max(`date`),
  GROUP_CONCAT(Description),
  GROUP_CONCAT(Notes)
FROM table1
GROUP BY id