SQL Server查询不同的行

Question

如何查询不同的客户？这是我的桌子..

CustID  DATE    PRODUCT
=======================
1       Aug-31  Orange
1       Aug-31  Orange
3       Aug-31  Apple   
1       Sept-24 Apple
4       Sept-25 Orange

这就是我要的.

# of New Customers            DATE
========================================
2                            Aug-31 
1                            Sept-25    

谢谢!

Answer 1

这有点棘手.您想要计算客户出现的第一个日期,然后进行汇总:

select mindate, count(*) as NumNew
from (select CustId, min(Date) as mindate
      from table t
      group by CustId
     ) c
group by mindate