jquery - MySql 的 UNION 和 ORDER

Question

我使用了以下查询，但显示错误。

SELECT 
    id as number,id,parentid,videoid,subject,name,created,message 
FROM 
    umqlh_hdflv_comments 
WHERE 
    `parentid` = '0' 
    AND `published` = '1' 
    AND `videoid` = '8' 
ORDER BY 
    number DESC,
    parentid 
UNION ( 
    SELECT 
        parentid as number,id,parentid,videoid,subject,name,created,message 
    FROM 
        umqlh_hdflv_comments 
    WHERE 
        `parentid` != '0' 
        AND `published` = '1' 
        AND `videoid` = '8'
    )

MySQL 说:文档

#1221 - Incorrect usage of UNION and ORDER BY

我该如何解决？

Answer 1

ORDER BY需要应用在完整的sql语句的末尾，

SELECT 
    id as number,
    id,
    parentid,
    videoid,
    subject,
    name,
    created,
    message 
FROM 
    umqlh_hdflv_comments 
WHERE 
    `parentid` = '0' 
    AND `published` = '1' 
    AND `videoid` = '8' 
 UNION ( 
    SELECT 
        parentid as number,
        id,
        parentid,
        videoid,
        subject,
        name,
        created,
        message 
    FROM 
        umqlh_hdflv_comments 
    WHERE 
        `parentid` != '0' 
        AND `published` = '1' 
        AND `videoid` = '8'
    )
    ORDER BY number DESC,parentid 

Reference .