Question

我有以下内容：

我现在尝试为一年中的每周添加一行，并相应地过滤联系人。 CONTACTS有一个datetime列。新表格如下：

        Status 1    Status 2    Status 3
Week 1      3          4           2
Week 2      1          5           3
Week 3      2          2           4

我认为需要使用DATEADD，但是我在如何开始更改查询方面感到茫然。

我知道MySQL有一个GROUP BY WEEK命令，但我不认为SQL有一个等价的。实现这一目标的最佳方法是什么？

Answer 1

如果数据跨越多年，您可以使用DATEPART()，按周和年份分组：

SELECT 
    'Week ' + cast(datepart(wk, created) as varchar(2)) Week,
    SUM(case WHEN status = 1 then 1 else 0 end) Status1,
    SUM(case WHEN status = 2 then 1 else 0 end) Status2,
    SUM(case WHEN status = 3 then 1 else 0 end) Status3,
    SUM(case WHEN status = 4 then 1 else 0 end) Status4,
    SUM(case WHEN status = 5 then 1 else 0 end) Status5
FROM contacts
group by datepart(wk, created), year(created)

请参阅SQL Fiddle with Demo

将年份添加到最终结果中：

SELECT 
    'Week ' + cast(datepart(wk, created) as varchar(2)) Week,
    year(created) year,
    SUM(case WHEN status = 1 then 1 else 0 end) Status1,
    SUM(case WHEN status = 2 then 1 else 0 end) Status2,
    SUM(case WHEN status = 3 then 1 else 0 end) Status3,
    SUM(case WHEN status = 4 then 1 else 0 end) Status4,
    SUM(case WHEN status = 5 then 1 else 0 end) Status5
FROM contacts
group by  datepart(wk, created), year(created)

请参阅SQL Fiddle with demo

Answer 2

您可以使用the datepart function从日期中提取一周。

查询变为：

SELECT datepart(week, created) as week,
  SUM(case WHEN status = 1 then 1 else 0 end) Status1,
  SUM(case WHEN status = 2 then 1 else 0 end) Status2,
  SUM(case WHEN status = 3 then 1 else 0 end) Status3,
  SUM(case WHEN status = 4 then 1 else 0 end) Status4,
  SUM(case WHEN status = 5 then 1 else 0 end) Status5
FROM contacts
group by datepart(week, created)

SqlFiddle：http://sqlfiddle.com/#!6/226ae/6tsq

Answer 3

您可以尝试在查询中使用group by子句：

SELECT
    DATE_FORMAT( created, '%u' ) week_number,
    SUM(case WHEN status = 1 then 1 else 0 end) Status1,
    SUM(case WHEN status = 2 then 1 else 0 end) Status2,
    SUM(case WHEN status = 3 then 1 else 0 end) Status3,
    SUM(case WHEN status = 4 then 1 else 0 end) Status4,
    SUM(case WHEN status = 5 then 1 else 0 end) Status5
FROM contacts
GROUP BY DATE_FORMAT( created, '%u' )

我假设你在谈论mysql。

此处记录了DATE_FORMAT函数：
http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_date-format

使用SQL进行GROUP BY WEEK

3 个答案: