MySql從多行選擇值到一行

Question

我有一個表格，其中有4行保存了DateTime值。

查詢：

SELECT row1, row2, row3, row4 FROM table; 

顯示了這種結果：

+------------+------------+------------+------------+ 
| row1 | row2 | row3 | row4 | 
+------------+------------+------------+------------+ 
|01.01.2014 |null  |null  |31.12.2018 | 
|null  |17.08.2015 |01.12.2050 |null  | 
|02.01.2010 |null  |28.03.2067 |null  | 
+------------+------------+------------+------------+ 

但我想這些日期像結合起來，整理成一排：

+------------+ 
| rows | 
+------------+ 
|01.01.2014 | 
|02.01.2010 | 
|17.08.2015 | 
|01.12.2050 | 
|28.03.2067 | 
|31.12.2018 | 
+------------+ 

怎麼查詢我必須用來獲得我想要的結果？

在此先感謝

Answer 1

SELECT row1 AS rows FROM table WHERE row1 IS NOT NULL 
UNION ALL 
SELECT row2 AS rows FROM table WHERE row2 IS NOT NULL 
UNION ALL 
SELECT row3 AS rows FROM table WHERE row3 IS NOT NULL 
UNION ALL 
SELECT row4 AS rows FROM table WHERE row4 IS NOT NULL 
ORDER BY rows DESC; 

會做你想要我猜。

您是否有更多關於該問題的信息，例如表名和列名。