SQL多重条件CASE WHEN和或

如何解决SQL多重条件CASE WHEN和或

我加入了两个表（tbl1和tbl2）。两个表中都存在AnimalNo，但这是tbl1的主键，并且可以在tbl2中多次出现（如果AnimalNo与多个ConditionID相关联）

tbl1

AnimalNo  |   KillDate
1         |   01/01/2019
2         |   01/01/2019
3         |   01/01/2019
4         |   01/01/2020
5         |   01/01/2020

tbl2

AnimalNo  |   ConditionID
1         |   1
1         |   2
2         |   1
3         |   1
3         |   2 
4         |   1
5         |   1
5         |   2         

在上面的示例中，我想要一个表，该表中我得到具有每种条件的AnimalID的计数以及都具有AnimalNo 1和2的ConditionID的计数：

Year  |  N_killed   |  Type1   | Type2    | Both 
2019  |  3          | 3        | 2        |  2      
2020  |  2          | 2        | 1        |  1      

我有这个查询，可以成功告诉我每个单独的AnimalNo的{​​{1}}的数量，但是我想添加最后一个称为ConditionID的列，该列具有Both同时具有AnimalNo 1和2

ConditionID

解决方法

我想这就是你想要的

SELECT
  
  DATEPART(year,tbl1.KillDate) AS KillYear,COUNT(Distinct tbl1.AnimalNo) AS N_Killed,COUNT(CASE WHEN tbl2.ConditionId =9 THEN 1 END) AS Type1a,COUNT(CASE WHEN tbl2.ConditionId =75 THEN 1 END) AS Type1b,COUNT(CASE WHEN tbl2.ConditionId =23 THEN 1 END) AS Type2a,COUNT(CASE WHEN tbl2.ConditionId =81 THEN 1 END) AS Type2b,COUNT(CASE WHEN tbl2.ConditionId IN (9,75) OR tbl2.ConditionId IN (23,81) BothTypes
FROM tbl1 LEFT JOIN
     tbl2 ON tbl1.AnimalNo = tbl2.AnimalNo
WHERE YEAR(tbl1.KillDate) >=2012
GROUP BY DATEPART(year,KillDate)
ORDER BY DATEPART(year,KillDate)

,

尝试一下：

declare @tbl1 table
(
AnimalNo int,KillDate date
)

insert into @tbl1(AnimalNo,KillDate)
select 1,'2019-01-01' union
select 2,'2019-01-01' union
select 3,'2019-01-01' union
select 4,'2020-01-01' union
select 5,'2020-01-01'

declare @tbl2 table
(
AnimalNo int,ConditionID int
)

insert into @tbl2(AnimalNo,ConditionID)
select 1,1 union
select 1,2 union
select 2,1 union
select 3,2 union
select 4,1 union
select 5,2


select
year(k.KillDate) as [Year],count(distinct k.AnimalNo) as N_Killed,sum(c.Type1),sum(c.Type2),sum(case when c.Type1 = 1 and c.Type2 = 1 then 1 else 0 end) as Both
from

@tbl1 k

JOIN
(
select 
c.AnimalNo,max(case when c.ConditionID = 1 then 1 else 0 end) as Type1,max(case when c.ConditionID = 2 then 1 else 0 end) as Type2
from
@tbl2 c
group by c.AnimalNo
) c
on k.AnimalNo = c.AnimalNo
group by year(k.KillDate)