有没有办法在一个语法中选择两个具有不同子查询的计数？

Question

基本上，我想得到两个计数。第一个计数是记录数。第二个计数是包含数据的记录数。这两个计数来自名为调查的表，该表并不包含所有州的名称。因此，我将它与另一个表UsState连接起来，以获得所有州的名称。我把语法放在一起，但我得到了一个错误。

SELECT
Name as State,
count (*)from NamrsFrozen2017.Investigation2017 where FiscalYear = 2017 AND StateName in (SELECT distinct StateName FROM [NamrsFrozen2017].[Investigation2017] WHERE (not ReportDate = '' ))[Report Date Records],
count (*) from NamrsFrozen2017.Investigation2017 WHERE FiscalYear = 2017 AND ReportDate != '' AND StateName in (SELECT distinct StateName FROM [NamrsFrozen2017].[Investigation2017] WHERE (not ReportDate = '' ))[Report Date Records with Data]
From
(SELECT DISTINCT Name FROM NamrsFullDw.UsState) s
LEFT JOIN NamrsFrozen2017.Investigation2017 c ON s.Name = c.StateName AND  c.FiscalYear = 2017
  GROUP BY Name
  Order by Name

Answer 1

一些相关子查询会对您有所帮助。它们看起来像内联selects，但使用对内联查询外部的表的引用。如下所示：

SELECT 
   Name as State,
   (SELECT COUNT(*) 
    FROM NamrsFrozen2017.Investigation2017 
    --I would think you want to view count of records for the current state, and not ALL states
    -- and not ALL states. So filter like this:
    WHERE FiscalYear = 2017 AND StateName = s.Name -- <-Correlated
    --Don't need a full list, like you had before
    -- (SELECT distinct StateName FROM [NamrsFrozen2017].[Investigation2017] WHERE (not ReportDate = '' ))
   ) AS [Report Date Records],
   (SELECT COUNT(*) 
    FROM NamrsFrozen2017.Investigation2017 
    WHERE FiscalYear = 2017 AND StateName = s.Name -- <- correlated
        AND ReportDate != '' --or maybe ReportDate IS NOT NULL            
    --Don't need to query the full table after correlating this to your FROM clause
    --  in (SELECT distinct StateName FROM [NamrsFrozen2017].[Investigation2017] WHERE (not ReportDate = '' ))
   ) AS [Report Date Records with Data]
FROM
   (SELECT DISTINCT Name FROM NamrsFullDw.UsState) s
   LEFT JOIN NamrsFrozen2017.Investigation2017 c 
        ON s.Name = c.StateName AND c.FiscalYear = 2017
GROUP BY s.Name
ORDER BY s.Name

这可能会优化得更多，但我不熟悉您的数据，也不清楚您到底想要用原始查询完成什么。

Answer 2

评论太长了。

出现语法错误是因为内联子查询的格式不正确。不能从COUNT(*)函数开始；它们都需要是完全形式的SELECT语句。然后每一个都需要用括号括起来。

这就是您的查询应该是什么样子。

SELECT
  Name AS State
 ,(
    SELECT
      COUNT(*)
    FROM
      NamrsFrozen2017.Investigation2017
    WHERE
      FiscalYear = 2017
      AND StateName IN
          (
            SELECT DISTINCT StateName
            FROM NamrsFrozen2017.Investigation2017
            WHERE ReportDate <> ''
          )
  ) AS [Report Date Records]
 ,(
    SELECT
      COUNT(*)
    FROM
      NamrsFrozen2017.Investigation2017
    WHERE
      FiscalYear = 2017
      AND ReportDate != ''
      AND StateName IN
          (
            SELECT DISTINCT StateName
            FROM NamrsFrozen2017.Investigation2017
            WHERE (NOT ReportDate = '')
          )
  ) AS [Report Date Records with Data]
FROM
  (SELECT DISTINCT Name FROM NamrsFullDw.UsState) AS s
LEFT JOIN
  NamrsFrozen2017.Investigation2017 AS c
    ON
    s.Name = c.StateName
      AND c.FiscalYear = 2017
GROUP BY
  Name
ORDER BY
  Name;

这里还有一个次要问题，那就是这个查询是否会做您期望它做的事情。根据Larnu在评论中的观点，聚合函数在不同的环境中以不同的方式处理NULL。但是，如果没有样本数据进行测试，我就不能断定这个正常运行的查询版本是否会返回您想要的结果。