Question

我有一个完整的大脑屁时刻，所以我想我会在这里问。我有3个看起来像这样的表

设备表

EquipmentID | LocationID 
-------------------------
1           | 2
2           | 2
3           | 1
4           | 2
5           | 3
6           | 3

位置表

LocationID | LocationName
--------------------------
1          | Pizza Hut
2          | Giordanos
3          | Lou Malnati's

服务表

LocationID | EquipmentID | Status 
-----------------------------------
2          | 1           | Serviced
2          | 2           | Not Yet Serviced
2          | 4           | Not Yet Serviced
3          | 5           | Serviced

我需要一种方法来列出已经维修过一台或多台设备的所有地点，但并非该地点的所有设备都已经过维修。

因此，对于上面的示例，它将返回以下结果

LocationID | ServicedEquipmentID  | NotServicedEquipmentIDS   | LocationStatus
------------------------------------------------------------------------------
2          | 1                    | 2, 4                      | Partially Serviced
3          | 5                    | 6                         | Partially Serviced

感谢您的帮助！

Answer 1

此查询将为您提供所需的位置状态，但不是单个设备状态：

SELECT  [LocationId]
       ,[LocationId]
       ,CASE ( [IsServiced] + [IsNotServiced] )
          WHEN 0 THEN 'Not Serviced'
          WHEN 1 THEN 'Partially Serviced'
          WHEN 2 THEN 'Serviced'
        END [LocationStatus]
FROM    ( SELECT    [l].[LocationId]
                   ,[e].[LocationId]
                   ,CASE [s].[Status]
                      WHEN 'Serviced' THEN 1
                      ELSE 0
                    END [IsServiced]
                   ,CASE [s].[Status]
                      WHEN 'Not Yet Serviced' THEN 1
                      ELSE 0
                    END [IsNotServiced]
          FROM      [Location] l
                    INNER JOIN [Equipment] e ON [l].[LocationId] = [e].[LocationId]
                    INNER JOIN [Service] s ON [l].[LocationId] = [s].[LocationId]
                                              AND [e].[EquipmentId] = [s].[EquipmentId]
        ) x

要将已经/未被服务的设备ID的逗号分隔列表添加到结果集，您将需要某种类型的CONCAT功能。 UDF，CLR或递归CTE（我现在没时间写这个 - here's a link）。

SQL查询帮助

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