我这样写的对不对

我怎么写的都比你们复杂多了 select t3.ci_id ,wm_concat(select t2.stu_name from pm_ci t1 cross join pm_siu t2 group by t1.ci_id where t3.ci_id=t1.ci_id having instr(t1.stu_ids,'1')>0 or instr(t1.stu_ids,'2')>0 or instr(t1.stu_ids,'3')>0 or instr(t1.stu_ids,'4')from pm_ti t3;