mysql统计有多少组_MYSQL统计一个班有多少个学生

create temporary table classname select 1 as cid, '小一班' as cid_name union all select 2, '小二班' union all select 3, '小三班' union all select 4, '中一班' union all select 5, '中二班' union all select 6, '中三班' union all select 7, '大一班' union all select 8, '大二班';

create temporary table temp2 select 1 as sid, '张一' as sid_name, 2 as cid union all select 2, '张二', 1 union all select 3, '张三', 1 union all select 4, '张四', 3 union all select 5, '张五', 2 union all select 6, '张六', 5 union all select 7, '张七', 6 union all select 8, '张八', 6;

SQL联表怎么写？

回复讨论(解决方案)

继续求指点....

SELECT temp2.cid,classname.cid_name,count(temp2.cid) counts,GROUP_CONCAT(temp2.sid_name) names FROM classname,temp2 WHERE classname.cid=temp2.cid GROUP BY temp2.cid;

本条技术文章来源于互联网，如果无意侵犯您的权益请点击此处反馈版权投诉

本文系统来源：php中文网