select deptno,avg(sal)
from emp group by deptno
having avg(sal) =
(select max(avg(sal)) from emp group by deptno);
from emp group by deptno
having avg(sal) =
(select max(avg(sal)) from emp group by deptno);
2018-02-19
最新回答 / 180416
select d.deptno,d.dname,count(e.empno) from emp e right join dept d on e.deptno=d.deptno group by d.deptno,d.dname;等同于右外連接;兩種語句區(qū)別也不大,但是外連接的符號(hào)位置不常用估計(jì)會(huì)記錯(cuò)。
2018-02-17
SELECT CI_ID,WM_CONCAT(STU_NAME)
FROM ( SELECT A.CI_ID,B.STU_NAME
FROM PM_CI A, PM_STU B WHERE INSTR(A.STU_IDS,B.STU_ID)>0)
GROUP BY CI_ID
FROM ( SELECT A.CI_ID,B.STU_NAME
FROM PM_CI A, PM_STU B WHERE INSTR(A.STU_IDS,B.STU_ID)>0)
GROUP BY CI_ID
2018-01-10
select t.ci_id, wm_concat(stu_name)
from pm_ci t ,pm_stu d
where instr(t.stu_ids,d.stu_id)>0
group by t.ci_id
from pm_ci t ,pm_stu d
where instr(t.stu_ids,d.stu_id)>0
group by t.ci_id
2017-12-26