T-SQL：AVG功能

Question

你能帮我找一下'Count_of_Attno'数据集的AVG吗？

AttNo as'Count_of_Attno'是nvarchar。

SELECT CONVERT(CHAR(10), ArrDateTime, 120) as [Date],
       count(AttNo) as Count_of_Attno
FROM [dbo].[Main]
GROUP BY CONVERT(CHAR(10), ArrDateTime, 120)
Order by CONVERT(CHAR(10), ArrDateTime, 120) desc

谢谢！

Answer 1

这是一种在没有子查询的情况下获得平均值的简单方法：

SELECT COUNT(AttNo) / COUNT(DISTINCT CONVERT(CHAR(10), ArrDateTime, 120)) as avg_count
FROM [dbo].[Main];