按组计数查询

Question

我有一些类别和种族群体，我需要对报告进行查询，看起来像这样

现在我有查询可以按客户ID和种族统计。然而，他也是技巧，客户端表有西班牙语字段（位0假1真）。客户可以有任何种族，但同时他/她可以是西班牙裔。 我现在的查询可以计算客户端，但对于西班牙裔，它只列出计数而不是按种族划分

select ethnicity, COUNT (c.EthnCode) as '(A) tottal Numbers of participamts by Rase', 
(select COUNT (Hispanic) from clients c JOIN ethnicity e
ON c.EthnCode = e.EthnCode
where c.EthnCode in ('N','A','B','P','W','NW','AW','BW','BN') and Hispanic =1 )as '(B)Number of Hispanic or Latino Participants Reported in Column A by Race'
from  Clients c
JOIN ethnicity e
ON c.EthnCode = e.EthnCode
where c.EthnCode in ('N','A','B','P','W','NW','AW','BW','BN')
group by ethnicity

此外，如果某些种族没有参与者，它只是没有在结果中显示，但我需要为该种族显示0。 这是我查询的结果

如你所见，西班牙裔不按类别划分。 需要帮助试图解决这个问题第二天仍然没有任何成功

Answer 1

试试这个：

select ethnicity, COUNT (c.EthnCode) as '(A) tottal Numbers of participamts by Rase', 
sum(case when Hispanic=1 then 1 else 0 end) as '(B)Number of Hispanic or Latino Participants Reported in Column A by Race'
from  Ethnicity E
LEFT JOIN Clients C
ON c.EthnCode = e.EthnCode
where e.EthnCode in ('N','A','B','P','W','NW','AW','BW','BN')
group by ethnicity

SUM（CASE ...）在实际计数中用作一种“子计数”。

<强>更新：

为了将所有其他代码归为“其他倍数”类别，请执行以下操作：

select 
    case 
    when e.EthnCode in ('N','A','B','P','W','NW','AW','BW','BN') then ethnicity
    else 'Other Multiples' 
    end as ethnicity, 
    COUNT (c.EthnCode) as '(A) tottal Numbers of participamts by Rase', 
    sum(case when Hispanic=1 then 1 else 0 end) as '(B)Number of Hispanic or Latino Participants Reported in Column A by Race'
from  Ethnicity E
LEFT JOIN Clients C
ON c.EthnCode = e.EthnCode
group by case 
    when e.EthnCode in ('N','A','B','P','W','NW','AW','BW','BN') then ethnicity
    else 'Other Multiples' 
    end

这假设种族中不在您的硬编码语句中的所有民族代码都是倍数。