SQL：在“选择为子查询”中选择

我有以下声明：

select 
    product_name as ShortestLength = (select top 1 product_name, len(fact_name) Value_Length 
                                      from table 
                                      order by Value_Length, fact_name ASC)

select
    'Product' as Column_Name,
    avg(case when product is null then 1.000 else 0 end) * 100 as PctMissing,
    count(product) as TotalCount,
    count(distinct product) as UniqueCount
from 
    table

select
    'Product' as Column_Name,
    avg(case when product is null then 1.000 else 0 end)*100 as PctMissing,
    count(product) as TotalCount,
    count(distinct product) as UniqueCount,
(select top 1 product_name from table order by Value_Length, fact_name ASC) as ShortestLength 
from table

返回此输出：

shortestlength
PS

我想将此结果添加到另一个select语句中：

select 
    product_name as ShortestLength = (select top 1 product_name, len(fact_name) Value_Length 
                                      from table 
                                      order by Value_Length, fact_name ASC)

select
    'Product' as Column_Name,
    avg(case when product is null then 1.000 else 0 end) * 100 as PctMissing,
    count(product) as TotalCount,
    count(distinct product) as UniqueCount
from 
    table

select
    'Product' as Column_Name,
    avg(case when product is null then 1.000 else 0 end)*100 as PctMissing,
    count(product) as TotalCount,
    count(distinct product) as UniqueCount,
(select top 1 product_name from table order by Value_Length, fact_name ASC) as ShortestLength 
from table

因此，结果将是：

列名 pctmissing 总数 唯一计数 最短长度 产品 5.100 181186 15 附言

---

您可以使用条件聚合：

select 'Product' as Column_Name,
        avg(case when t.product is null then 1.000 else 0 end)*100 as PctMissing,
        count(t.product) as TotalCount,
        count(distinct t.product) as UniqueCount,
        max(case when seqnum = 1 then product_name end) as shortest_length
from (select t.*,
             row_number() over (order by len(fact_name), fact_name) as seqnum
      from table t 
     ) t

---

这假设两个

表

引用实际上是同一个表。

您可以使用第一个查询作为子查询，而不是select语句中的列：

select 
    product_name as ShortestLength = (select top 1 product_name, len(fact_name) Value_Length 
                                      from table 
                                      order by Value_Length, fact_name ASC)

select
    'Product' as Column_Name,
    avg(case when product is null then 1.000 else 0 end) * 100 as PctMissing,
    count(product) as TotalCount,
    count(distinct product) as UniqueCount
from 
    table

select
    'Product' as Column_Name,
    avg(case when product is null then 1.000 else 0 end)*100 as PctMissing,
    count(product) as TotalCount,
    count(distinct product) as UniqueCount,
(select top 1 product_name from table order by Value_Length, fact_name ASC) as ShortestLength 
from table

---

您的第一个查询在语法上看起来不正确。我认为它应该生成一个语法错误。请使用您正在使用的数据库进行标记。

PS

此处是否为productname？