SQL两个表联合计算指令写法
小白求问，筛选男生数大于1个的class的数量
select class,made_quantity from
(select class,case when gender=="男" then count(id) as made_quantity from a left join b on name group by class) as c
when c.made_quantity > 1;
小白求问，筛选男生数大于1个的class的数量
select class,made_quantity from
(select class,case when gender=="男" then count(id) as made_quantity from a left join b on name group by class) as c
when c.made_quantity > 1;