Question

mysql选择不同表格中的多个列和日期和日期分组

Answer 1

我建议union all然后汇总：

select date, user, sum(vale)
from ((select t1.user, t1.date, t1.vale from t1) union all
      (select t2.user, t2.date, t2.vale from t2)
     ) t
group by date, user;

如果只想要一个用户（外部查询或每个子查询）的结果，可以添加where user = 'x'。

Answer 2

在派生表中提取年份和月份，并执行union all。然后GROUP BY结果：

select y, m, user, sum(vale)
from
(
    select user, year(date) as y, month(date) as m, vale from t1
    union all
    select user, year(date) as y, month(date) as m, vale from t2
) dt
group by y, m, user

mysql从不同的表中选择乘以列的值和按日期分组

2 个答案: