Question

我有一张表：

Status | Quantity | PeriodDate
------------------------------
100    | 2        | 2013-07-02
100    | 3        | 2013-07-02
100    | 5        | 2013-07-02
100    | 3        | 2013-07-03
100    | 1        | 2013-07-03
100    | 0        | 2013-07-04
100    | 0        | 2013-07-04
100    | 5        | 2013-07-04
100    | 6        | 2013-07-05
100    | 4        | 2013-07-06
100    | 8        | 2013-07-06

我需要选择数据，以便显示某个范围内每个不同日期的数量。我原本以为我可以做点什么：

SELECT DISTINCT PeriodDate, SUM(Quantity) as TotalQuantity where PeriodDate BETWEEN '2013-07-02' AND '2013-07-04'

但是这会返回一行，其中包含所有数量的总和。

我喜欢这样的事情：

TotalQuantity | PeriodDate
--------------------------
10            | 2013-07-02
4             | 2013-07-03
5             | 2013-07-04
6             | 2013-07-05

我如何实现这一目标？

Answer 1

SELECT PeriodDate, 
       SUM(Quantity) as TotalQuantity 
from your_table
where PeriodDate BETWEEN '2013-07-02' AND '2013-07-05'
group by PeriodDate

Answer 2

区别同时适用于PeriodDate和TotalQuantity。您需要使用DISTINCT。

，而不是使用GROUP BY

SELECT PeriodDate, SUM(Quantity) as TotalQuantity 
FROM ???
WHERE PeriodDate BETWEEN '2013-07-02' AND '2013-07-04'
GROUP BY PeriodDate

解释：Distinct用于消除结果集中的重复行。

进一步解释：http://www.mysqltutorial.org/mysql-distinct.aspx

MySQL查询在同一个表上的查询中

2 个答案: