Question

我确定有人可以轻松回答这个问题，这会让我已经很穷的大脑受伤。

我有一个用户表：

created_date
id
user_type

我正在尝试在MYSQL中编写一个查询，该查询将从今天起计算30天，然后通过user_type回吐每天新增用户的数量（预计有些天可能为0）

想要一个类似于：

的结果

date:      | count(id[user_type = 1]) | count (id[user_type = 2])
2015-02-09           10                      9
2015-02-08            0                      10
2015-02-07            8                      0

依旧......

谢谢！

Answer 1

使用GROUP BY，并查看时间函数http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html#function_day

... GROUP BY MONTH(created_date), DAY(created_date)

Answer 2

这是一种可行的方法。 [http://sqlfiddle.com/#!2/090e19/24]

select
    date_sub(date(now()), interval (d0.n0 + d1.n1 * 5) day),
    count(case when user_type = 1 then 1 else null end),
    count(case when user_type = 2 then 1 else null end)
from
    (select 0 as n0 union all select 1 union all select 2 union all select 3 union all select 4) as d0
    cross join
    (select 0 as n1 union all select 1 union all select 2 union all select 3 union all select 4 union all select 5) as d1
    left outer join users as u on u.created_date = date_sub(date(now()), interval (d0.n0 + d1.n1 * 5) day)
        and u.created_date >= date_sub(date(now()), interval 29 day)
group by date_sub(date(now()), interval (d0.n0 + d1.n1 * 5) day)
order by date_sub(date(now()), interval (d0.n0 + d1.n1 * 5) day) desc;

mysql按天和上一个月计算记录和属性

2 个答案: