MySQL的：有兩個不同的列查詢不同的列日期

Question

，我有以下結果從查詢

SELECT DISTINCT user_id, 
       IF(ra.status = 1, created_datetime, 'No record') AS ACTIVATED, 
       IF(ra.status = 0, created_datetime, 'No record') AS DE_ACTIVATED 
FROM accounts ra 
WHERE user_id IN (12345678); 

+----------+---------------------+---------------------+ 
| user_id | ACTIVATED   | DE_ACTIVATED  | 
+----------+---------------------+---------------------+ 
| 12345678 | No record   | 2013-04-28 02:32:36 | 
| 12345678 | 2013-03-28 02:32:36 | No record   | 
+----------+---------------------+---------------------+ 

我想只有1行的記錄，結合激活和去激活。基本上，這樣做。

+----------+---------------------+---------------------+ 
| user_id | ACTIVATED   | DE_ACTIVATED  | 
+----------+---------------------+---------------------+ 
| 12345678 | 2013-03-28 02:32:36 | 2013-04-28 02:32:36 | 
+----------+---------------------+---------------------+ 

任何幫助是非常感謝，因爲我建立我的查詢忍者技能。

問候

Answer 1

以這兩個條件的MAX，但要「假」條件評估爲null。然後把它包在COALESCE所以如果calcualted MAX爲null，它會與no record替代：

SELECT user_id, 
    COALESCE(MAX(IF(ra.status = 1, created_datetime, null)), 'No record') AS Activated, 
    COALESCE(MAX(IF(ra.status = 0, created_datetime, null)), 'No record') AS Deactivated 
FROM accounts ra 
WHERE user_id IN (12345678) 

如果你會查詢一個以上的用戶，這添加到末尾：

GROUP BY user_id