其实就是full join mysql不支持,我现在知道两个表的情况下可以模拟full join select if(a.id is null,b.id,a.id)as id, a.name,a.sex,b.course,b.score from a left join b on a.id=b.id union select if(a.id is null,b.id,a.id)as id,a.name,a.sex,b.course,b.score from a right join b on a.id=b.id; 现在问题是,如果是3个表我就搞懵了 望高人指点
mysql不支持,我现在知道两个表的情况下可以模拟full join
select if(a.id is null,b.id,a.id)as id, a.name,a.sex,b.course,b.score from a left join b on a.id=b.id
union
select if(a.id is null,b.id,a.id)as id,a.name,a.sex,b.course,b.score from a right join b on a.id=b.id;
现在问题是,如果是3个表我就搞懵了
望高人指点