如何对 sql 中的两个聚合字段求和

Question

我想得到以下信息：

患者人数
索赔数量
总计数（即 Patient_Count + Claim_Count）

select  year, 
    count(distinct patientid) as Patitent_Count, 
    Count(distinct CLAIMID) as Claims_Count,
    sum(Patitent_Count + Claims_Count) as Total_count 
    from sand_scipher_ds_db.ATS.sym
    group by year
    order by year

错误：

SQL compilation error: Aggregate functions cannot be nested: [COUNT(DISTINCT SYM.PATIENTID)] nested in [SUM(PATITENT_COUNT + CLAIMS_COUNT)]*

我还尝试了以下子查询：

select x.*,
sum(x.Patitent_Count + x.Number_of_claim) as Total_count
from( 
  select  year, count(distinct patientid) as Patitent_Count, Count(distinct CLAIMID) as Number_of_claim from sand_scipher_ds_db.ATS.sym
  group by year
  order by year)x
  group by year
  order by year

但是仍然出现同样的错误任何人都可以建议一种方法吗？

Answer 1

您可以使用子查询来做到这一点：

select  year, Patitent_Count, Claims_Count, Patitent_Count + Claims_Count as Total_Count
from(select  year, 
count(distinct patientid) as Patitent_Count, 
Count(distinct CLAIMID) as Claims_Count
from sand_scipher_ds_db.ATS.sym
group by year) t
order by year

Answer 2

你甚至不需要子查询:

select
    year,
    count(distinct patientid) Patitent_Count,
    count(distinct CLAIMID) Claims_Count,
    count(distinct patientid) + count(distinct CLAIMID) as Total_Count
from sand_scipher_ds_db.ATS.sym
group by year
order by year

Answer 3

在 snowflake 中更容易，只需通过您命名输出列的别名将它们相加即可。 Snowflake 见 total_count 是从两个聚合函数结果派生的，因此不需要添加到 GROUP BY 子句中。相当整洁。

SELECT  
    year, 
    COUNT(DISTINCT patientid) AS patitent_count, 
    COUNT(DISTINCT claimid) AS claims_count,
    patitent_count + claims_count AS total_count 
FROM sand_scipher_ds_db.ats.sym
GROUP BY 1
ORDER BY 1;

在其他数据库中，您已经像在 eshirvana 答案中那样写了相同的 SQL 2 次以上，或者使用子查询。

如何对 sql 中的两个聚合字段求和

How to sum two aggregated fields in sql

sql

select

group-by

aggregate

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