mysql的排序問題與ORDER BY

Question

我有這樣

d 1 
b 3 
a 5 
c 2 
c 4 
c 6 

表時，我寫SELECT DISTINCT c1 FROM table ORDER BY c2它採取C值，並返回6形式C2;

d 
b 
a 
c 

但我想它返回

d 
c 
b 
a 

我怎麼能這樣做？

編輯：
其實c2是日期列。

Answer 1

SELECT c1 FROM table GROUP BY c1 ORDER BY MIN(c2)

Answer 2

TRY INSTEAD OF

SELECT DISTINCT c1 FROM table ORDER BY c 

SELECT c1, MIN(c2) AS minC2 FROM table GROUP BY c1 ORDER BY c2 

Answer 3

SELECT c1 
FROM 
(SELECT c1, c2 FROM tbl GROUP BY c1 ORDER BY c1, c2) X 
ORDER BY c2 

使MySQL的使用有序GROUP BY收集，內部查詢將只挑最小的C2記錄不明確使用MIN。外部查詢然後按（min）c2值正確排序。