如果不查会员组，两个表查询就OK了，关联KS_Article.KS_ArticleInput和KS_User.UserName，要查会员组的话还得关联KS_User.GroupID和KS_UserGroup.ID

Select TOP 1 ka.*,ku.*,kg.* from KS_Article as ks,KS_User.as ku,KS_UserGroup as kg Where Ka.ID={$CurrInfoID} and ka.ArticleInput=ku.UserName and Ku.UserGroup=kg.ID

没有做测试，请楼主代劳！