SQL Server查詢返回1行的今天日期對多個列計數

Question

我想寫一個SQL Server查詢與1行作爲客戶的多個區域的日期戳記。它爲每個case語句返回一行。

Customer Region 
1   A 
2   A 
3   B 
4   B 
5   B 

SELECT 
CONVERT(VARCHAR(10), GETDATE(), 111), 
case when Region = 'A' then COUNT(Customer) end as 'Region A', 
case when Region = 'B' then COUNT(Customer) end as 'Region B', 
FROM tbl_Customers 

結果：

Date  Region A Region B 
2017/06/07 2   NULL 
2017/06/07 NULL  3 

Answer 1

你只需要添加的聚合函數內CASE表達：

SELECT CONVERT(VARCHAR(10), GETDATE(),111) [Date], 
     COUNT(CASE WHEN Region = 'A' THEN Customer END) [Region A], 
     COUNT(CASE WHEN Region = 'B' THEN Customer END) [Region B] 
FROM tbl_Customers;