Every derived table must have its own alias
这个是SQLSELECT comusername,comuserid,saytext,saytime,writername,writerid FROM (SELECT a.username as comusername,a.userid as comuserid,a.saytext,a.saytime,b.username as writername,b.userid as writerid FROM ***_enewspl a left join ***_ecms_blog b on a.id=b.id WHERE 1 AND b.classid=26) union all (SELECT a.username as comusername,a.userid as comuserid,a.saytext,b.username as writername,b.userid as writerid FROM ***_enewspl a left join ***_ecms_photo b on a.id=b.id WHERE 1 AND b.classid=37) LIMIT 8
这个是SQLSELECT comusername,comuserid,saytext,saytime,writername,writerid FROM (SELECT a.username as comusername,a.userid as comuserid,a.saytext,a.saytime,b.username as writername,b.userid as writerid FROM ***_enewspl a left join ***_ecms_blog b on a.id=b.id WHERE 1 AND b.classid=26) union all (SELECT a.username as comusername,a.userid as comuserid,a.saytext,b.username as writername,b.userid as writerid FROM ***_enewspl a left join ***_ecms_photo b on a.id=b.id WHERE 1 AND b.classid=37) LIMIT 8
left join ***_ecms_blog b on a.id=b.id WHERE 1 AND b.classid=26)
union all
(SELECT a.username as comusername,a.userid as comuserid,a.saytext,b.username as writername,b.userid as writerid FROM ***_enewspl a left join ***_ecms_photo b on a.id=b.id WHERE 1 AND b.classid=37) bb LIMIT 8
(SELECT a.username as comusername,a.userid as comuserid,a.saytext,a.saytime,b.username as writername,b.userid as writerid FROM
`***_enewspl` a
left join `***_ecms_blog` b on a.id=b.id WHERE 1 AND b.classid=26
union all
SELECT a.username as comusername,a.userid as comuserid,a.saytext,b.username as writername,b.userid as writerid FROM `***_enewspl` a left join `***_ecms_photo` b on a.id=b.id WHERE 1 AND b.classid=37)
bb LIMIT 8注意你的表名,修改一下