我分析应先这样
select *
from pm_ci a,pm_stu b
然后
select a.ci_id,instr(a.stu_ids,b.stu_id)
from pm_ci a, pm_stu b;
前面有个例子
select deptno,wm_concat(ename) from emp group by deptno;
之后又这样一下
select deptno,ename from emp;
然后就卡住了
改成这个样子就可以了select deptno, (select min(sal) from emp where deptno = e.deptno) from emp egroup by deptnohaving (select min(sal) from emp where deptno = e.deptno ) > (select min(sal) from emp where deptno =20);
select a.ci_id,wm_concat(b.stu_name) stu_names
from teacher_lbh a,student_lbh b
where instr(a.stu_ids,b.stu_id)>0
group by a.ci_id
但是查询结果 并不是按照张三 李四。。。排序的
