[英]SQL Case with no null
When I run this query: 当我运行此查询时:
select
'1992' = CASE WHEN Year(HireDate) = 1992 THEN count(*) END,
'1993' = CASE WHEN Year(HireDate) = 1993 THEN count(*) END,
'1994' = CASE WHEN Year(HireDate) = 1994 THEN count(*) END
from employees
group by Year(HireDate)
I get: 我明白了:
1992 1993 1994
3 NULL NULL
NULL 3 NULL
NULL NULL 3
How can I change the query to get: 如何更改查询以获取:
1992 1993 1994
3 3 3
With this query you will get only a row: 使用此查询,您将只获得一行:
select
'1992'=
count( CASE WHEN Year(HireDate) = 1992 THEN 1 END ),
'1993' =
count( CASE WHEN Year(HireDate) = 1993 THEN 1 END ),
'1994' =
count( CASE WHEN Year(HireDate) = 1994 THEN 1 END )
from employees
select
'1992' = sum (case when year(HireDate) = 1992 THEN 1 else 0 END),
'1993' = sum (case when year(HireDate) = 1993 THEN 1 else 0 END),
'1994' = sum (case when year(HireDate) = 1994 THEN 1 else 0 END),
from employees
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