Question

我正在尝试获取特定日期的字段WOID的计数，问题是日期字段[opendate]是日期时间字段，所以我决定使用强制转换将[opendate]更改为日期字段

SELECT distinct
   cast([OPENDATE] as date) as [Opened Date]
  ,count([WOID]) as ID
FROM [Tasks]
Group by [OPENDATE]

问题是我得到这样的输出

Opened date ID 
2014-05-01  1
2014-05-01  1
2014-05-21  1 
2014-05-20  1

我期望得到像这样的正确计数

Opened date ID 
2014-05-01  4
2014-05-02  5

任何想法

Answer 1

您按照与所选内容不同的内容进行分组，请更改为：

SELECT cast([OPENDATE] as date) as [Opened Date]
      ,count([WOID]) as ID
FROM [Tasks]
Group by cast([OPENDATE] as date)

您可能在每个日期之后计算了不同的WOID，在这种情况下您将使用：

SELECT cast([OPENDATE] as date) as [Opened Date]
      ,count(DISTINCT [WOID]) as ID
FROM [Tasks]
Group by cast([OPENDATE] as date)

作为一般规则，SELECT中的所有非汇总项都应包含在GROUP BY中。 DISTINCT变得多余，可以排除。

Answer 2

提供：

SELECT distinct
   cast([OPENDATE] as date) as [Opened Date]
  ,count([WOID]) as ID
FROM [Tasks]
Group by cast([OPENDATE] as date)

一个镜头 - 您希望将其分组到date，而不是datetime - 模仿您选择的列

Answer 3

我假设你想要一个不同的WOID计数。如果是这样的话：

SELECT 
   cast([OPENDATE] as date) as [Opened Date]
  ,count(distinct [WOID]) as ID
FROM [Tasks]
Group by cast([OPENDATE] as date)

Answer 4

更复杂的解决方案如下：

首先，您将收到所需格式的集：

SELECT cast([OPENDATE] as date) as [Opened Date] ,[WOID] as ID
FROM [Tasks]

然后，使用上述内容，您可以根据需要执行分组和计数，例如：

SELECT [Opened Date], ID = count([WOID])
FROM
(
    SELECT cast([OPENDATE] as date) as [Opened Date], [WOID]
    FROM [Tasks]
) x
Group by [Opened Date]

如果要计算每个数据的WOID的唯一值，可以按如下方式修改查询：

SELECT [Opened Date], ID = count(distinct [WOID])
FROM
(
    SELECT cast([OPENDATE] as date) as [Opened Date], [WOID]
    FROM [Tasks]
) x
Group by [Opened Date]

如果要使用窗口函数，查询可能如下所示：

SELECT distinct
   cast([OPENDATE] as date) as [Opened Date] ,
   count([WOID]) over (partition by cast([OPENDATE] as date) order by [WOID]) as ID
FROM [Tasks]

难倒集团

4 个答案: