Question

我的结果显示两个计数相同但应该有一些具有不同的计数，因为CarCode有时为空。

SELECT  distinct car.carKey,            
    car.Weight,
    car.CarCode,
    COUNT(car.carKey)OVER(PARTITION BY car.carKey) AS TotalCarKeyCount,
    COUNT(Case When (car.[Weight] IS not null) and (car.CarCode is null) as CarCountWithoutCode 
           then 0 
       else car.carKey End) OVER(PARTITION BY car.carKey) AS CarCount
from car

结果显示TotalCarKeyCount和CarCountWithoutCode始终具有相同的计数，例如case语句不起作用。

Answer 1

听起来您可能想要使用SUM()代替：

SELECT  distinct car.carKey,            
    car.Weight,
    car.CarCode,
    COUNT(car.carKey)OVER(PARTITION BY car.carKey) AS TotalCarKeyCount,
    SUM(Case When (car.[Weight] IS not null) and (car.CarCode is null) as CarCountWithoutCode 
           then 0 else 1 End) OVER(PARTITION BY car.carKey) AS CarCount
from car

SQL Fiddle demo显示了使用COUNT()和SUM()：

之间的区别

create table test
(
  id int
);

insert into test values
(1), (null), (23), (4), (2);

select 
  count(case when id is null then 0 else id end) [count],
  sum(case when id is null then 0 else 1 end) [sum]
from test;

Count返回5并且Sum返回4.或者您可以更改COUNT()以使用null，null值将被排除在最终count()

select 
  count(case when id is null then null else id end) [count],
  sum(case when id is null then 0 else 1 end) [sum]
from test;

您的查询将是：

SELECT  distinct car.carKey,            
    car.Weight,
    car.CarCode,
    COUNT(car.carKey)OVER(PARTITION BY car.carKey) AS TotalCarKeyCount,
    COUNT(Case When (car.[Weight] IS not null) and (car.CarCode is null) as CarCountWithoutCode 
           then null else 1 End) OVER(PARTITION BY car.carKey) AS CarCount
from car

Answer 2

将then 0更改为then null。零值被计算，空值不计算。

基于Or的计数不区分计数

2 个答案: