选择不包含在分组依据中的列答案

【问题标题】：Select column not included in group by选择不包含在分组依据中的列
【发布时间】：2014-07-24 18:38:12
【问题描述】：

我有以下 SQL Server 脚本：

SELECT
    cicmpy.cmp_name as Naam
    ,c2.cmp_name as Arts
    ,cicmpy.textfield1 as Voornaam
    ,items.UserField_02 as Label
    ,absences.HID
FROM
    Absences
INNER JOIN 
    cicmpy ON Absences.CustomerID = cicmpy.cmp_wwn
INNER JOIN 
    cicmpy as c2 ON Absences.FreeGuidField_01 = c2.cmp_wwn
INNER JOIN 
    Items ON absences.ItemCode = items.ItemCode
WHERE 
    Absences.Type = 86

我需要 SELECT 语句中的所有列，但只需要唯一的列。事实上，HID 列是唯一列，因此对其进行分组会返回所有行。我试图通过CTE 实现我的目标，但没有成功。如何根据除HID 列之外的列获取所有唯一记录？

【问题讨论】：

您只想区分这些列？
为什么还要返回 HID？您要退回哪个 HID？一组中可以有多个 HID。
你能给我们一些样本数据和你想要的结果吗？听起来您可能只需要使用select distinct...。
请告诉我们您当前的输出是什么样的以及您想要的输出。

标签： sql sql-server tsql

【解决方案1】：

使用SELECT DISTINCT

SELECT DISTINCT
 cicmpy.cmp_name as Naam
,c2.cmp_name as Arts
  ,cicmpy.textfield1 as Voornaam
  ,items.UserField_02 as Label
FROM Absences
  INNER JOIN cicmpy
    ON Absences.CustomerID = cicmpy.cmp_wwn
inner join cicmpy as c2
   on Absences.FreeGuidField_01 = c2.cmp_wwn
inner join Items
   on absences.ItemCode = items.ItemCode
where Absences.Type = 86

或

如果您想要一些 HID，则需要选择要使用的聚合类型（MIN 或 MAX）

SELECT 
   cicmpy.cmp_name as Naam
  ,c2.cmp_name as Arts
  ,cicmpy.textfield1 as Voornaam
  ,items.UserField_02 as Label
  , MAX(Absences.HID) as MAX_HID
  , MIN(Absences.HID) as MIN_HID
FROM Absences
  INNER JOIN cicmpy
    ON Absences.CustomerID = cicmpy.cmp_wwn
inner join cicmpy as c2
   on Absences.FreeGuidField_01 = c2.cmp_wwn
inner join Items
   on absences.ItemCode = items.ItemCode
where Absences.Type = 86
GROUP BY 
   cicmpy.cmp_name
  ,c2.cmp_name
  ,cicmpy.textfield1
  ,items.UserField_02

【讨论】：

【解决方案2】：

希望这是您正在寻找的：

;WITH cte AS
(
SELECT

 cicmpy.cmp_name as Naam
,c2.cmp_name as Arts
  ,cicmpy.textfield1 as Voornaam
  ,items.UserField_02 as Label
  ,absences.HID
  ,ROW_NUMBER() OVER (PARTITION BY cicmpy.cmp_name, c2.cmp_name, cicmpy.textfield1, items.UserField_02 ORDER BY absences.HID DESC) AS rn
FROM
  Absences
  INNER JOIN cicmpy
    ON Absences.CustomerID = cicmpy.cmp_wwn
inner join cicmpy as c2
on Absences.FreeGuidField_01 = c2.cmp_wwn
inner join Items
on absences.ItemCode = items.ItemCode
where Absences.Type = 86   
)
SELECT *
FROM cte
WHERE rn = 1

【讨论】：