假设两个表为a,b 关联字段为 bh一对一关联selec * from a inner join b on a.bh=b.bh左关联selec * from a left join b on a.bh=b.bh右关联selec * from a right join b on a.bh=b.bh全关联selec * from a full join b on a.bh=b.bh
表和表之间关系很多的,你没说清楚啊 一对一?一对多?多对多?用主外建联系