Question

我有一个如下查询......

SELECT 
   contents.id, contents.title, contents.createdBy,
 (SELECT userGroup FROM suser_profile WHERE userId = 
         (SELECT users.id 
          FROM 
            users 
          WHERE 
            login = contents.createdBy)
    ) as userGroupID
FROM 
   contents 
WHERE
   contents.id > 0   
   AND contents.contentType = 'News' 
   **AND userGroupID = 3**
LIMIT 0, 10

当我尝试在WHERE子句中分配 userGroupID 时，SQL会触发一条错误，指出SQL错误（1054）：“where子句”中的未知列“userGroupID”

同时，如果我做了如下所示的小改动，

SELECT 
   contents.id, contents.title, contents.createdBy
FROM 
   smart_cms_contents 
WHERE
   contents.id > 0   
   AND contents.contentType = 'News' 
   **AND (SELECT userGroup FROM user_profile WHERE userId = 
         (SELECT users.id 
          FROM 
            users 
          WHERE 
            users.login = contents.createdBy)
    ) = 3**
LIMIT 0, 10

然后查询工作正常。

我必须使用多个 userGroupID 检查，这样，第二个样式会使查询变大，我必须有一个像第一个样式，任何帮助赞赏。

*注意：表名不是我在项目中使用的原始名称。如果表名中有错误，您可以忽略它。我主要担心的是在WHERE子句中使用通过 AS 分配给变量的值。

忽略查询中的STARS *

Answer 1

使用HAVING。例如：

WHERE
    contents.id > 0   
  AND
    contents.contentType = 'News'
HAVING
    userGroupID = 3
LIMIT 0, 10

Answer 2

如果我正确理解您的初始查询，那么我相信您想要做的是加入：

SELECT DISTINCT 
   contents.id, contents.title, contents.createdBy
FROM
   contents INNER JOIN users
      ON contents.createdBy = users.login
   INNER JOIN user_profile
      ON user_profile.userId = users.id
WHERE
   contents.id > 0   
   AND contents.contentType = 'News' 
   AND user_profile.userGroupID = 3
LIMIT 0, 10

Answer 3

完全不是你问的问题的答案，但是......

SELECT DISTINCT c.id, c.title, c.createdBy, s.userGroup AS userGroupID
FROM contents AS c
INNER JOIN users AS u
  ON c.createdBy = u.login
INNER JOIN suser_profile AS s
  ON s.userId = u.id
WHERE c.id > 0
  AND c.contentType = 'News'
  AND s.userGroup = 3

如何在WHERE子句中使用MYSQL“AS”返回值？

3 个答案: