SQL刪除與JOIN多個條件中的另一個表WHERE NULL

Question

我必須從slaveTable中刪除與masterTable表（死關係，從masterTable中刪除）沒有更多關係的行。

我想出了聲明：

DELETE 
FROM slaveTable AS s 
LEFT JOIN 
     masterTable AS m 
ON (s.key1 = m.key1 
AND s.key2 = m.key2) 
WHERE m.key1 IS NULL 

SQL DELETE with JOIN another table for WHERE condition 顯示這樣的解決方案......但不會爲我工作。 由於我缺乏聲譽，我無法在那裏回答。

Answer 1

指定要刪除行的表格。

DELETE s     -- << HERE: s (alias of slaveTable) 
FROM slaveTable AS s 
LEFT JOIN 
     masterTable AS m 
ON (s.key1 = m.key1 
AND s.key2 = m.key2) 
WHERE m.key1 IS NULL