php - MySql 删除不工作

Question

我有一个 mysql 删除脚本，它给我一个错误:

1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'LEFT JOIN mall ON mall.m_id = unifo.mids WHERE mallnames = 'My Mall'' at line 2

删除查询:

DELETE FROM unifo 
LEFT JOIN mall ON mall.m_id = unifo.mids 
WHERE mallnames = 'My Mall' && time_insert < NOW( ) - INTERVAL 25 
MINUTE 

我找不到我的错误

Answer 1

你在这个查询中有一个基本问题

DELETE FROM unifo 
LEFT JOIN mall ON mall.m_id = unifo.mids 
WHERE mallnames = 'My Mall' && time_insert < NOW( ) - INTERVAL 25 
MINUTE

你对 mall 表执行左连接，然后根据 mall 值你要删除一些东西，但在左连接中 mallname 可以为 null 没有左连接的意义

2 指定表

从 unifo 中删除 unifo ....