ホームページ >バックエンド開発 >PHPチュートリアル >请帮忙解释一下,多表联查,小弟我看太不懂,谢啦
请帮忙解释一下,多表联查,我看太不懂,,谢啦
<!--Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->select * from (select bookid,count(bookid) as degree from tb_borrow group by bookid) as borr join (select b.*,c.name as bookcasename,p.pubname,t.typename from tb_bookinfo b left join tb_bookcase c on b.bookcase=c.id join tb_publishing p on b.ISBN=p.ISBN join tb_booktype t on b.typeid=t.id where b.del=0) as book on borr.bookid=book.id order by borr.degree desc limit 10
select * from ( select bookid,count(bookid) as degree from tb_borrow group by bookid )as borr join ( select b.*,c.name as bookcasename,p.pubname,t.typename from tb_bookinfo b left join tb_bookcase c on b.bookcase=c.id join tb_publishing p on b.ISBN=p.ISBN join tb_booktype t on b.typeid=t.id where b.del=0 ) as book on borr.bookid=book.id order by borr.degree desc limit 10<div class="clear"> </div>