MySQL允许在where子句

Question

这是我的SQL语句，我无法运行未知列错误：

SELECT fm . * , mp.first_name, mp.last_name, mp.image, mp.member_id 
FROM featured_members AS fm 
JOIN member_profiles AS mp WHERE fm.member_id = mp.member_id 
AND fm.member_type_id =6 
AND fm.site_id =1 

当我运行它，它给了我#1054 - Unknown column 'fm.site_id' in 'on clause'错误

是否有语法问题，因为FM表确实有那个site_id列，但我不知道为什么SQL不提取它？

我对featured_members表结构是这样的：

1 sr_no  
2 member_id  
3 member_type_id 
4 site_id 

和member_profiles结构：

1 member_profile_id 
2 member_id  
3 first_name  
4 middle_name 
5 last_name  
6 gender 
7 image 

Answer 1

你就错了： 随着JOIN的它是强制性使用ON子句，除非另外它是一个交叉连接。

SELECT fm . * , mp.first_name, mp.last_name, mp.image, mp.member_id 
FROM featured_members AS fm 
JOIN member_profiles AS mp ON (fm.member_id = mp.member_id) 
WHERE fm.member_type_id =6 
AND fm.site_id =1 

Answer 2

测试：

SELECT fm.*, mp.first_name, mp.last_name, mp.image, mp.member_id 
FROM featured_members AS fm 
LEFT JOIN member_profiles AS mp ON fm.member_id = mp.member_id 
WHERE fm.member_type_id =6 AND fm.site_id =1 

Answer 3

“ON” 的条款中缺少您的查询和MySQL需要它。因此，Moddom提供的解决方案在我看来是正确的答案。

请参阅http://dev.mysql.com/doc/refman/5.0/en/join.html以及http://bugs.mysql.com/bug.php?id=13551。

Answer 4

尝试......

SELECT fm . * , mp.first_name, mp.last_name, mp.image, mp.member_id 
FROM featured_members AS fm, member_profiles AS mp 
WHERE fm.member_id = mp.member_id 
AND fm.member_type_id =6 
AND fm.site_id =1 

在你的语句中的JOIN子句期待相应的其上是什么原因造成的错误

Answer 5

试试这个： -

SELECT fm . * , mp.first_name, mp.last_name, mp.image, mp.member_id <br> 
FROM featured_members fm , member_profiles mp <br> 
where fm.member_id = mp.member_id <br> 
AND fm.member_type_id =6 <br> 
AND fm.site_id =1