php - SQL语法错误

Question

这是我的查询:

$query="Delete b
Where Exists 
    (
        Select 1
        From a
        Where a.poster_password = '$pass'
        And a.ad_id = '$id'
        And a.classified_id = b.classified_id
    )
Delete a
Where a.poster_password = '$pass'
And a.ad_id = '$id'";

我收到此错误:

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 'Where Exists ( Select 1 From a Where a.poster_p' at line 2

如果您需要更多意见，请告诉我...

这里出了什么问题？

谢谢

UDP日期:

只是一个问题:我是否还需要指定 a =“此表”和 b =“另一个表”，还是 MySql 通过此代码获取该值？

至于发布的新代码在哪里使用 FROM 和终止符分号，将无法工作并给出此错误:

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 'Delete FROM a Where a.poster_password = 'xxxxxxxxxxxxxxxxxxxxx' at line 10

更新2:

$query="Delete FROM $sql_table
        Where Exists 
        (
            Select 1
            From classified
            Where classified.poster_password = '$pass'
            And classified.ad_id = '$id'
            And classified.classified_id = $sql_table.classified_id
        );
        Delete FROM classified
        Where classified.poster_password = '$pass'
        And classified.ad_id = '$id'";

当我 echo $query 时:(在本例中，fordon 是 $sql_table 变量。)

Delete FROM fordon 
Where Exists 
(  
     Select 1 
     From classified 
     Where classified.poster_password = 'xxxxx' 
     And classified.ad_id = 'motorbat_166250627' 
     And classified.classified_id = fordon.classified_id 
 ); 
 Delete FROM classified 
 Where classified.poster_password = 'xxxxx' 
 And classified.ad_id = 'motorbat_166250627'

再次感谢

Answer 1

您没有指定要从中删除的表。尝试:

$query="Delete FROM b
Where Exists 
    (
        Select 1
        From a
        Where a.poster_password = '$pass'
        And a.ad_id = '$id'
        And a.classified_id = b.classified_id
    );
Delete FROM a
Where a.poster_password = '$pass'
And a.ad_id = '$id'";

我还在第一个 DELETE 查询结束后添加了分号。如果您想同时运行这两个版本，则在运行第二个版本之前需要一个分隔符来终止第一个查询。

回复。您的问题编辑有关 MySQL“获取”表的问题 - 如果 a 和 b 是此处的别名，那么不，MySQL 不会不知道 a 和 b 是什么。您需要为表添加别名，或将 a 和 b 替换为实际的表名称。