子查询中的访问别名答案

【问题标题】：Access alias in subquery子查询中的访问别名
【发布时间】：2011-07-15 21:36:36
【问题描述】：

我需要从子查询中的外部查询访问别名，就像这段代码一样。除了它不工作。有没有办法做到这一点？我的目标是为每个 OwnerIdName 制作这些聚合函数，这是我能想到的唯一方法。我正在使用 SQL Server 2008。

谢谢

SELECT Incident.OwnerIdName as OIN
  ,(SELECT COUNT(*)
    FROM Incident 
    WHERE CreatedOn BETWEEN '2011/1/1' AND '2011/1/31'
    AND Incident.OwnerIdName = OIN ) as CasesOpened
  ,(SELECT COUNT(*)
    FROM IncidentResolution 
    WHERE ActualEnd BETWEEN '2011/1/1' AND '2011/1/31'
            AND Incident.OwnerIdName = OIN ) as CasesClosed
FROM Incident

【问题讨论】：

标签： sql sql-server tsql

【解决方案1】：

你不能直接使用列名吗..？喜欢..

SELECT Inc.OwnerIdName as OIN
  ,(SELECT COUNT(*)
    FROM Incident 
    WHERE CreatedOn BETWEEN '2011/1/1' AND '2011/1/31'
    AND Incident.OwnerIdName = Inc.OwnerIdName ) as CasesOpened
  ,(SELECT COUNT(*)
    FROM IncidentResolution 
    WHERE ActualEnd BETWEEN '2011/1/1' AND '2011/1/31'
            AND Incident.OwnerIdName = Inc.OwnerIdName ) as CasesClosed
FROM Incident Inc

如果您想直接使用别名，则必须在查询的早期执行此操作，然后将其用于所有标量子查询。..

SELECT INC.OIN
  ,(SELECT COUNT(*)
    FROM Incident 
    WHERE CreatedOn BETWEEN '2011/1/1' AND '2011/1/31'
    AND Incident.OwnerIdName = INC.OIN ) as CasesOpened
  ,(SELECT COUNT(*)
    FROM IncidentResolution 
    WHERE ActualEnd BETWEEN '2011/1/1' AND '2011/1/31'
            AND Incident.OwnerIdName = INC.OIN ) as CasesClosed
from 
(Select OwnerIdName OIN
  FROM Incident) INc

【讨论】：

谢谢。我没想到。 :)

【解决方案2】：

试试这个（适用于 >= SQL 2005）：

WITH 
    CreatedQry AS
    (
        SELECT OwnerIdName, COUNT(1) AS CreatedCount
          FROM  Incident 
        WHERE CreatedOn BETWEEN '2011/1/1' AND '2011/1/31'
    ),
    EndQry AS
    (
        SELECT OwnerIdName, COUNT(1) AS EndCount
          FROM  IncidentResolution  
        WHERE ActualEnd  BETWEEN '2011/1/1' AND '2011/1/31'
    )
    SELECT  CreatedQry.OwnerIdName, CreatedCount, EndCount
      FROM  CreatedQry LEFT JOIN EndQry
        ON  CreatedQry.OwnerIdName = EndQry.OwnerIdName

【讨论】：