MySQL--Delete语句别名+LIMIT

在MySQL中，可以使用LIMIT来限制删除的数量，但部分写法并不支持LIMIT.

LIMIT方式

对于查询：
SELECT * FROM T1 LIMIT 1;
可以转换成：
DELETE FROM T1 LIMIT 1;

别名方式：

## 使用别名
DELETE T FROM T1 AS T;

但MySQL不支持别名+LIMIT方式，如：

查询：
SELECT * FROM T1 AS T LIMIT 1;
不能转换为：
DELETE T FROM T1 AS T LIMIT 1;

 

对于多表关联操作，同样不允许别名+LIMIT操作，但可以将LIMIT放入子查询中：

对于查询：
SELECT * FROM TB_1 AS T1
LEFT JOIN TB_2 AS T2
ON T1.ID = T2.ID
WHERE T2.ID IS NULL
LIMIT 10;

不能修改为：
DELETE T1 
FROM TB_1 AS T1
LEFT JOIN TB_2 AS T2
ON T1.ID = T2.ID
WHERE T2.ID IS NULL
LIMIT 10;

需要转换为：
DELETE T1 
FROM TB_1 AS T1
(SELECT T1.ID
FROM TB_1 AS T1
LEFT JOIN TB_2 AS T2
ON T1.ID = T2.ID
WHERE T2.ID IS NULL
LIMIT 10) AS T3 
INNER JOIN TB_2 AS T2
ON T1.ID=T2.ID