select * from a ,(select * from b ,c on b.cid(+)=c.cid) t on a.bh(+)=t.bh(+); 我理解的这个就是多个表之间的关联
select a.id, wm_concat(b.bh), c.gh, a.gc, a.name, a.xm, c.gdw, c.gds from a join b on a.bh = b.bh left join c on b.cid = c.id group by a.id, c.gh, a.gc, a.name, a.xm, c.gdw, c.gds
on a.bh(+)=t.bh(+);
我理解的这个就是多个表之间的关联
from a
join b
on a.bh = b.bh
left join c
on b.cid = c.id
group by a.id, c.gh, a.gc, a.name, a.xm, c.gdw, c.gds