如何将SQL Server出现在另一列中？

Question

ID      Offered  SalesID ItemID  DateTime
------------------------------------------
123456     1     36     1       2015-08-17  
123456     1     36     2       2015-08-17  
123456     1     36     3       2015-08-17  

如何计算值为1的Offered列在另一列中出现3次？

Answer 1

将表连接到子查询，该子查询查找Offered值的频率：

select s.*, OfferedCount
from (select Offered, count(*) OfferedCount
      from Sales group by Offered) c
join Sales s on s.Offered = c.Offered

请参阅live demo。

Answer 2

WITH cte AS (
    SELECT * FROM (VALUES
        (123456, 1, 36, 1, '2015-08-17'),  
        (123456, 1, 36, 2, '2015-08-17'),  
        (123456, 1, 36, 3, '2015-08-17')  
    ) AS x(ID, Offered, SalesID, ItemID, DateTime)
)
SELECT *, 
    SUM(CASE WHEN Offered = 1 THEN 1 ELSE 0 END) OVER (PARTITION BY ID) AS OfferedCount
FROM cte

如果您的Offered列只是一个列，您只需将其汇总而不是我已获得的CASE表达式来简化它。