MySQL的語法WHERE子句

Question

我嘗試使用下面的查詢在這裏http://i.imgur.com/XTlAv.png

我的表更新row 3(id=8)：

UPDATE player_ban 
    SET until = Now(), 
     unbanned_by = "MrSnare", 
     unbanned_reason = "test", 
     unbanned_date = Now() 
WHERE name = "MCYasman" 
    & unbanned_by = NULL 
    & until > NOW(); 

查詢正在運行，但沒有行被更新。

什麼問題？

我正在使用phpMyAdmin。

Answer 1

我會改變您的查詢使用AND而不是&和unbanned_by IS NULL。所以查詢將是：

UPDATE player_ban 
SET until = Now(), 
    unbanned_by = "MrSnare", 
    unbanned_reason = "test", 
    unbanned_date = Now() 
WHERE name = "MCYasman" 
    AND unbanned_by IS NULL 
    AND until > now(); 

的值永遠不會= null，你必須使用IS NULL。

Answer 2

不使用&，使用AND代替

WHERE name = "MCYasman" AND unbanned_by IS NULL AND until > now(); 

Answer 3

你需要改變你的unbanned_by支票使用 「爲空」，而不是 「= NULL」。像這樣。

UPDATE player_ban SET until = Now(), unbanned_by = "MrSnare", unbanned_reason = "test", unbanned_date = Now() WHERE name = "MCYasman" & unbanned_by is NULL & until > now(); 

NULL在SQL中不等於自己。

> select null = null, null is null, null is not null; 
+-------------+--------------+------------------+ 
| null = null | null is null | null is not null | 
+-------------+--------------+------------------+ 
|  NULL |   1 |    0 | 
+-------------+--------------+------------------+ 
1 row in set (0.00 sec)