例子選的太爛了吧,明明不需要用到子查詢就可以解決。就算是便于學(xué)生理解,也用深層次一點(diǎn)的例子好嗎
2018-11-06
select t2.ci_id, wm_concat(t1.stu_name)
from pm_stu t1, pn_ci t2
where instr(t2.stu_ids, t1.stu_id) > 0
group by t2.ci_id
看看提示還是挺簡單的
from pm_stu t1, pn_ci t2
where instr(t2.stu_ids, t1.stu_id) > 0
group by t2.ci_id
看看提示還是挺簡單的
2018-11-02
select cid,wm_concat(name) from ci,pm where instr(ci.sid,pm.sid)>0 group by cid;
2018-11-01
最新回答 / 慕田峪9362115
你外層加的關(guān)鍵字rownum 相當(dāng)于又使用了偽劣而不是普通列 肯定又不能用> ?>=符號了啊?select e2.r,empno,ename,salfrom (select rownum r,empno,ename,sal? ? ? ? ? ? from (select empno,ename,sal from emp order by sal desc ) e1? ? ? ? ? ? where rownum<=8) e2where e2.r >4
2018-08-29
select c.ci_id,(select wm_concat(stu_name) from pm_stu s where instr(c.stu_ids,s.stu_id)>0) stu_names
from pm_ci c
from pm_ci c
2018-08-28
select c.ci_id,wm_concat(s.stu_name) from pm_stu s,pm_ci c
where instr(c.STU_IDS,s.STU_ID)>0
group by c.ci_id;
where instr(c.STU_IDS,s.STU_ID)>0
group by c.ci_id;
2018-08-24
select * from (select * from emp order by sal desc)where rownum<=3這樣也是可以的
2018-08-22