根据日期获取用户数

Question

我有一个简单的表来存储用户 ID、用户名、电子邮件、注册日期...

RegistrationDate 是 DateTime 数据类型

当我要获取每个日期的用户数时，它会为每一行得到 1，因为它每一行都有一个唯一的 dateTime 戳。

SELECT DATEPART(dd, RegistrationDate) AS DD, COUNT(userID)   
FROM USER_Table 
GROUP BY RegistrationDate 
order by RegistrationDate DESC

如果我有 100 个注册用户，ABove 查询每 100 行获取一次。

我想根据日期进行计数。我尝试了不同的方法，但似乎没有任何效果。

Answer 1

试试这个：

SELECT Cast(RegistrationDate AS DATE),
       Count(userID)
FROM   User_Table
GROUP  BY Cast(RegistrationDate AS DATE)
ORDER  BY Cast(RegistrationDate AS DATE)DESC 

Answer 2

您需要按CAST(RegistrationDate as Date)分组

SELECT CAST(RegistrationDate as Date) AS [Date], COUNT(userID)   
FROM USER_Table 
GROUP BY CAST(RegistrationDate as Date)
order by CAST(RegistrationDate as Date) DESC

Answer 3

SELECT cast(RegistrationDate as Date) AS DD, COUNT(userID)   
FROM USER_Table 
GROUP BY cast(RegistrationDate as Date)
order by cast(RegistrationDate as Date) DESC