Question

如何计算总数？

SELECT 
    COUNT(CASE WHEN SHP.id = 1 then 1 ELSE NULL END) as "New", 
    COUNT(CASE WHEN SHP.id = 2 then 5 ELSE NULL END) as "Accepted"
from SHP

结果：

NEW  Accepted
 1       5

但我需要总数结果：6

Answer 1

我做这样的事情;

SELECT 
    COUNT(CASE WHEN id = 1 THEN 1 END) as New, 
    COUNT(CASE WHEN id = 2 THEN 5 END) as Accepted,
    COUNT(CASE WHEN id = 1 THEN 1 
               WHEN id = 2 THEN 5 END) as Total
FROM SHP

这正是CASE语句应该用于的，逻辑非常简单。这样可以避免在同一个字段上执行多次计算。

请注意，THEN语句中的值根本没有在此实例中使用，它只是在执行COUNT数字而不是执行{ {1}}。我还删除了SUM，因为无论如何这都是ELSE NULL默认执行的操作。

如果你的意图是CASE，那么就这样做;

SUM

示例

假设您的数据库中只有两个值，1和2，我们可以创建这样的测试数据;

SELECT SUM(CASE WHEN id = 1 THEN 1 END) as New, SUM(CASE WHEN id = 2 THEN 5 END) as Accepted, SUM(CASE WHEN id = 1 THEN 1 WHEN id = 2 THEN 5 END) as Total FROM SHP

并使用此查询;

CREATE TABLE #SHP (id int) INSERT INTO #SHP (id) VALUES (1),(2)

给出这个结果;

SELECT SUM(CASE WHEN id = 1 then 1 END) as New, SUM(CASE WHEN id = 2 then 5 END) as Accepted, SUM(CASE WHEN id = 1 THEN 1 WHEN id = 2 THEN 5 END) as Total FROM #SHP

Answer 2

试试这个：

SELECT 
    COUNT(CASE WHEN SHP.id = 1 then 1 ELSE NULL END) + 
    COUNT(CASE WHEN SHP.id = 2 then 5 ELSE NULL END) as "Total"
from SHP

Answer 3

您可以将查询包装到子查询中并执行以下操作：

SELECT SUM(New) as New, Sum(Accepted) as Accepted, Sum(New + Accepted) as Total FROM
(SELECT 
    COUNT(CASE WHEN SHP.id = 1 then 1 ELSE NULL END) as "New", 
    COUNT(CASE WHEN SHP.id = 2 then 5 ELSE NULL END) as "Accepted"
from SHP) as SubQuery

如果您不想重复计算并将两者加在一起，那就是这样。

Answer 4

试试这个

with s1 as(
SELECT 
    COUNT(CASE WHEN SHP.id = 1 then 1 ELSE 0 END) as "New" 
from SHP 
),s2 as
(
SELECT  
    COUNT(CASE WHEN SHP.id = 2 then 5 ELSE 0 END) as "Accepted"
from SHP 
)
select sum("New"+  "Accepted") from s1,s2

如何计算sql的数量

4 个答案:

试试这个