Question

我正在使用SQL Server。当我尝试使用datepart函数按周对信息进行排序时，它不返回任何值。我的表格中有所选日期范围的值。

我尝试使用的查询是：

Declare @StartDate datetime, @EndDate datetime
set @StartDate = '20120401 00:00:00'
set @EndDate = '20120430 23:59:59'
;WITH
mytablePlusHours As
(
SELECT *,
    DATEPART(ww, [eci_date])     AS [dateWeek]
FROM    [mytable]    
)
, mytableHourGroups As
(
SELECT  dateWeek, 
        [eci_country],
        COUNT(*)        As [Number_Country],
        ROW_NUMBER() OVER(PARTITION BY dateWeek ORDER BY [eci_country])
                        As [Country_Rank]
FROM        mytablePlusHours
GROUP BY    dateWeek, [eci_country]
)
SELECT  
    dateWeek     AS [eci_date],
    [eci_country],
    [Number_Country]
FROM    mytableHourGroups WITH(NOLOCK)
WHERE   [dateWeek] between @StartDate and @EndDate
ORDER BY [dateWeek], [Number_Country] DESC

我可以在白天提取信息，但我无法弄清楚如何按周分类。有人可以告诉我我的代码在哪里错了吗？谢谢！

我正在尝试显示我的数据：

Week Country       Count
16   United States  13
17   Canada         41

Answer 1

[DateWeek]不是日期，而是一个数字（1到53）。

要么...

将WHERE子句移动到您的第一个CTE。

mytablePlusHours As
(
  SELECT *, DATEPART(ww, [eci_date])     AS [dateWeek]
    FROM [mytable]
   WHERE [eci_date] between @StartDate and @EndDate
)

或者，将DATEPART()更改为返回日期的函数...

mytablePlusHours As
(
  SELECT *, DATEADD(WEEK, DATEDIFF(WEEK, 0, [eci_date]), 0) AS [dateWeek]
    FROM [mytable]
)

Answer 2

您将整数与日期进行比较。

DATEPART(ww...)返回数字周（即一年中第三周的3周）。您的比较为datetime，无法直接比较。

您需要与日期的周比较，您还应该检查年份。要检查一周：

WHERE   [dateWeek] between  DATEPART(ww,@StartDate) and DATEPART(ww,@EndDate)

您应该将年份添加到您的CTE并进行比较，否则1/15/2012和1/9/2011将同时显示在同一个“周”中。

SQL Server - 按datepart周排序

2 个答案: