2.1 內鏈接spa
select a.*,b.* FROM a INNER join b ON a.id = b.id; 查出全部.net
或者 select a.*,b.* FROM a join b on a.id=b.idblog
效果:bfc
2.2 外鏈接 http://blog.csdn.net/jintao_ma/article/details/51260458select