try: select a.* from article a inner join author b on a.id=b.article_id inner join submittor c on a.submittor_id=c.id where concat(b.firstname,b.middlename,b.lastname) like '%$keyword%' or (a.is_author=1 and concat(c.firstname,c.middlename,c.lastname) like '%$keyword%') 这里is_author=1算是作者吧
用left: select a.* from article a left join author b on a.id=b.article_id left join submittor c on a.submittor_id=c.id where concat(b.firstname,b.middlename,b.lastname) like '%$keyword%' or (a.is_author=1 and concat(c.firstname,c.middlename,c.lastname) like '%$keyword%')
select a.* from article a
inner join author b on a.id=b.article_id
inner join submittor c on a.submittor_id=c.id
where concat(b.firstname,b.middlename,b.lastname) like '%$keyword%' or (a.is_author=1 and concat(c.firstname,c.middlename,c.lastname) like '%$keyword%')
这里is_author=1算是作者吧
select a.* from article a
left join author b on a.id=b.article_id
left join submittor c on a.submittor_id=c.id
where concat(b.firstname,b.middlename,b.lastname) like '%$keyword%' or (a.is_author=1 and concat(c.firstname,c.middlename,c.lastname) like '%$keyword%')