帝国cms 联合多张表查询

$api->query("select * from ((select * from {$dbtbpre}custom_guanzhu) UNION (select * from {$dbtbpre}custom_newsguanzhu)) as a where a.Userid={$member[userid]} order by a.Createtime limit {$numsize},{$Pagesize}"); 

注意的是 必须保证 两个关联表有相同的字段。