select ci_id,substr(replace(stu_ids,',',''),2,1) a2 from pm_ci where ci_id='2'
)
select a,wm_concat(c) zuname from
(select a1.ci_id a,b.stu_name c from a1,pm_stu b where a1.a2=b.stu_id)
group by a
select ci_id,substr(replace(stu_ids,',',''),4,1) a2 from pm_ci where ci_id='1'
union all
select ci_id,substr(replace(stu_ids,',',''),1,1) a2 from pm_ci where ci_id='2'
union all
with a1 as
(select ci_id,substr(replace(stu_ids,',',''),1,1) a2 from pm_ci where ci_id='1'
union all
select ci_id,substr(replace(stu_ids,',',''),2,1) a2 from pm_ci where ci_id='1'
union all
