子查询没有按我想要的方式工作

Question

这是我第一次在 stackoverflow 上发帖。

我想查看每个 marital_status 的每个教育级别的最低、平均和最高工资是多少。 我试过这段代码，但它只显示所有不同教育水平的最小值、平均值和最大值：

Select distinct education, (select min(convert(int, income))
                            from [dbo].[marketing_campaign] where marital_status = 'Married' and year_birth > 1980 and income <> 0) Min_Married,
                            (select avg(convert(int, income))
                            from [dbo].[marketing_campaign] where marital_status = 'Married' and year_birth > 1980 and income <> 0) Avg_Married,
                            (select max(convert(int, income))
                            from [dbo].[marketing_campaign] where marital_status = 'Married' and year_birth > 1980 and income <> 0) Max_Married,
                            (select min(convert(int, income))
                            from [dbo].[marketing_campaign] where marital_status = 'Single' and year_birth > 1980 and income <> 0) Min_Single,
                            (select avg(convert(int, income))
                            from [dbo].[marketing_campaign] where marital_status = 'Single' and year_birth > 1980 and income <> 0) Avg_Single,
                            (select max(convert(int, income))
                            from [dbo].[marketing_campaign] where marital_status = 'Single' and year_birth > 1980 and income <> 0) Max_Single,
                            (select min(convert(int, income))
                            from [dbo].[marketing_campaign] where marital_status = 'together' and year_birth > 1980 and income <> 0) Min_together,
                            (select avg(convert(int, income))
                            from [dbo].[marketing_campaign] where marital_status = 'together' and year_birth > 1980 and income <> 0) Avg_together,
                            (select max(convert(int, income))
                            from [dbo].[marketing_campaign] where marital_status = 'together' and year_birth > 1980 and income <> 0) Max_together
from [dbo].[marketing_campaign]
where  education in ('master', 'Graduation', 'phd', 'basic')
group by education
order by education desc

提前致谢！

Answer 1

在您的子查询中与education 没有关联，当我怀疑您需要以下内容时，也不需要重复使用子查询：

with i as (
    select education, 
        Iif(marital_status = 'Married' , Convert(int, income),0) Income_Married,
        Iif(marital_status = 'Single'  , Convert(int, income),0) Income_Single,
        Iif(marital_status = 'together', Convert(int, income),0) Income_Together,
    from dbo.marketing_campaign
    where education in ('master', 'Graduation', 'phd', 'basic')
    and year_birth > 1980 and income != 0
)
select education, 
    Min(Income_Married) Min_Married,
    Avg(Income_Married) Avg_Married,
    Max(Income_Married) Max_Married,
    Min(Income_Single) Min_Single,
    Avg(Income_Single) Avg_Single,
    Max(Income_Single) Max_Single,
    Min(Income_Together) Min_Together,
    Avg(Income_Together) Avg_Together,
    Max(Income_Together) Max_Together
from i
group by education
order by education desc;

Answer 2

您可以简单地按照以下方式进行操作。我尝试制作与您在我的数据库中描述的相同的环境，所以希望这会对您有所帮助。

SELECT   DISTINCT C.education,
         MIN(income) OVER(PARTITION BY education) AS MIN_Married, 
         AVG(income) OVER(PARTITION BY education) AS AVG_Married, 
         MAX(income) OVER(PARTITION BY education) AS MAX_Married 
FROM     [dbo].[marketing_campaign] C
WHERE    education IN ('master', 'Graduation', 'phd', 'basic')
         AND marital_status = 'Married'
         AND year_birth > 1980
ORDER BY education DESC

Answer 3

使用条件聚合：

SELECT education, 
       MIN(CASE WHEN marital_status = 'Married' AND year_birth > 1980 AND income <> 0) THEN CONVERT(INT, income) END) Min_Married,
       AVG(CASE WHEN marital_status = 'Married' AND year_birth > 1980 AND income <> 0) THEN CONVERT(INT, income) END) Avg_Married,
       MAX(CASE WHEN marital_status = 'Married' AND year_birth > 1980 AND income <> 0) THEN CONVERT(INT, income) END)  Max_Married,
       MIN(CASE WHEN marital_status = 'Single' AND year_birth > 1980 AND income <> 0) THEN CONVERT(INT, income) END) Min_Single,
       AVG(CASE WHEN marital_status = 'Single' AND year_birth > 1980 AND income <> 0) THEN CONVERT(INT, income) END) Avg_Single,
       MAX(CASE WHEN marital_status = 'Single' AND year_birth > 1980 AND income <> 0) THEN CONVERT(INT, income) END) Max_Single,
       MIN(CASE WHEN marital_status = 'together' AND year_birth > 1980 AND income <> 0) THEN CONVERT(INT, income) END) Min_together,
       AVG(CASE WHEN marital_status = 'together' AND year_birth > 1980 AND income <> 0) THEN CONVERT(INT, income) END) Avg_together,
       MAX(CASE WHEN marital_status = 'together' AND year_birth > 1980 AND income <> 0) THEN CONVERT(INT, income) END) Max_together
FROM [dbo].[marketing_campaign]
WHERE education IN ('master', 'Graduation', 'phd', 'basic')
GROUP BY education
ORDER BY education DESC;

或者，移动WHERE子句中的常用条件：

SELECT education, 
       MIN(CASE WHEN marital_status = 'Married' THEN CONVERT(INT, income) END) Min_Married,
       AVG(CASE WHEN marital_status = 'Married' THEN CONVERT(INT, income) END) Avg_Married,
       MAX(CASE WHEN marital_status = 'Married' THEN CONVERT(INT, income) END)  Max_Married,
       MIN(CASE WHEN marital_status = 'Single' THEN CONVERT(INT, income) END) Min_Single,
       AVG(CASE WHEN marital_status = 'Single' THEN CONVERT(INT, income) END) Avg_Single,
       MAX(CASE WHEN marital_status = 'Single' THEN CONVERT(INT, income) END) Max_Single,
       MIN(CASE WHEN marital_status = 'together' THEN CONVERT(INT, income) END) Min_together,
       AVG(CASE WHEN marital_status = 'together' THEN CONVERT(INT, income) END) Avg_together,
       MAX(CASE WHEN marital_status = 'together' THEN CONVERT(INT, income) END) Max_together
FROM [dbo].[marketing_campaign]
WHERE education IN ('master', 'Graduation', 'phd', 'basic')
  AND year_birth > 1980 AND income <> 0
GROUP BY education
ORDER BY education DESC;