5

有一个大型数据库，我从中提取了一个研究人群。出于比较的目的，我想选择一个具有相似特征的对照组。我想匹配的两个标准是年龄和性别。为我提供匹配目的的数字的查询是

select sex, age/10 as decades,COUNT(*) as counts
        from
        (
            select distinct m.patid
                ,m.sex,DATEPART(year,min(c.admitdate)) -m.yrdob as Age
                from members as m
                inner join claims as c on c.patid=m.PATID
                group by m.PATID, m.sex,m.yrdob
        )x group by sex, Age/10

结果集看起来像

在此处输入图像描述

这个时代的十年列由表达式给出

(DATEPART(year,min(c.admitdate)) -m.yrdob)/10

这用于使用整数除法查找年龄范围为 20-29、30-39 等的人。例如，我想从更大的数据集中选择 507 位 20 多岁的女性。查找较大数据集特征的查询是

select distinct m.patid
        ,m.sex
        ,(DATEPART(year,min(c.admitdate)) -m.yrdob)/10 as decades
        from members as m
        inner join claims as c on c.patid=m.PATID
        group by m.PATID, m.sex,m.yrdob

编辑：第二个查询的结果 在此处输入图像描述

所以我需要sum第二个查询中的十年列在第一个查询中相等counts。我尝试的（并返回零结果）如下。我需要做什么来匹配这些年龄？

运行但不返回结果的查询：

select x.PATID--,x.sex,x.decades,y.counts
    from
    (

    select distinct m.patid
        ,m.sex
        ,(DATEPART(year,min(c.admitdate)) -m.yrdob)/10 as decades
        from members as m
        inner join claims as c on c.patid=m.PATID
        group by m.PATID, m.sex,m.yrdob
    ) as x 
    inner join 
    (

        select sex, age/10 as decades,COUNT(*) as counts
        from
        (
            select distinct m.patid
                ,m.sex,DATEPART(year,min(c.admitdate)) -m.yrdob as Age
                from members as m
                inner join claims as c on c.patid=m.PATID
                group by m.PATID, m.sex,m.yrdob
        )x group by sex, Age/10
    ) as y on x.sex=y.sex and x.decades=y.decades
    group by y.counts,x.PATID,x.sex,y.sex
    having SUM(x.decades)=y.counts and x.sex=y.sex
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1 回答 1

1 
select
   T1.sex,
   T1.decades,
   T1.counts,
   T2.patid

from (

   select 
      sex, 
      age/10 as decades,
      COUNT(*) as counts
   from (

      select  m.patid,
         m.sex,
         DATEPART(year,min(c.admitdate)) -m.yrdob as Age
      from members as m
      inner join claims as c on c.patid=m.PATID
      group by m.PATID, m.sex,m.yrdob
   )x 
   group by sex, Age/10
) as T1
join (
   --right here is where the random sampling occurs
    SELECT TOP 50--this is the total number of peolpe in our dataset
      patid
      ,sex
      ,decades

   from (
      select  m.patid,
         m.sex,
         (DATEPART(year,min(c.admitdate)) -m.yrdob)/10 as decades
      from members as m
      inner join claims as c on c.patid=m.PATID
      group by m.PATID, m.sex, m.yrdob

   ) T2
      order by NEWID()
) as T2
on T2.sex = T1.sex
and T2.decades = T1.decades

编辑：我发布了另一个与此类似的问题，我发现我的结果实际上并不是随机的，但它们只是前 N 个结果。我在最外层的查询中排序，newid()所做的只是围绕完全相同的结果集进行改组。从现在关闭的问题中，我发现我需要在上述查询的注释行中使用TOP关键字。order by newid()

于 2012-11-29T15:41:53.490 回答