是否使用主键创建视图？

Question

我用以下代码创建了一个视图

SELECT
    CONVERT(NVARCHAR, YEAR(okuma_tarihi)) + 'T1' AS sno,
    YEAR(okuma_tarihi) AS Yillar,
    SUM(toplam_kullanim_T1) AS TotalUsageValue, 'T1' AS UsageType
FROM
    TblSayacOkumalari
GROUP BY
    CONVERT(NVARCHAR, YEAR(okuma_tarihi)) + 'T1', YEAR(okuma_tarihi)

UNION ALL

SELECT
    CONVERT(NVARCHAR, YEAR(okuma_tarihi)) + 'T2' AS sno,
    YEAR(okuma_tarihi) AS Yillar,
    SUM(toplam_kullanim_T2) AS TotalUsageValue, 'T2' AS UsageType
FROM
    TblSayacOkumalari
GROUP BY
    CONVERT(NVARCHAR, YEAR(okuma_tarihi)) + 'T1', YEAR(okuma_tarihi)

UNION ALL

SELECT
    CONVERT(NVARCHAR, YEAR(okuma_tarihi)) + 'T3' AS sno,
    YEAR(okuma_tarihi) AS Yillar,
    SUM(toplam_kullanim_T3) AS TotalUsageValue, 'T3' AS UsageType
FROM
    TblSayacOkumalari
GROUP BY
    CONVERT(NVARCHAR, YEAR(okuma_tarihi)) + 'T1', YEAR(okuma_tarihi)

我想将CONVERT(nvarchar, YEAR(okuma_tarihi)) + 'T1' AS sno定义为主键，这可能吗？如果这是可能的，我该怎么办？

Answer 1

不能在视图上创建主键。在SQL Server中，您可以使用create an on a view，但这与创建主键不同。

如果你给我们更多的信息，为什么你想在你的视图上有一个键，也许我们可以帮助你。

Answer 2

您可能无法创建主键(每次)，但如果您的视图基于具有主键的表，并且该键包含在视图中，则主键也将反映在视图中。需要主键的应用程序可以接受视图，就像Lightswitch一样。

Answer 3

参加这个聚会有点晚了--但这也很有效：

CREATE VIEW [ABC].[View_SomeDataUniqueKey]
AS
SELECT 
CAST(CONCAT(CAST([ID] AS VARCHAR(4)), 
        CAST(ROW_NUMBER() OVER(ORDER BY [ID] ASC) as VARCHAR(4)) 
        )  AS int) AS [UniqueId]
,[ID]
FROM SOME_TABLE JOIN SOME_OTHER_TABLE
GO

在我的例子中，连接的结果是ID -主键被重复5次(关联不同的唯一数据)，其中的妙招是可以从每个UniqueID有效地确定原始ID ID+RowNumber() = 11，12，13，14，21，22，23，24等等。如果您将RowNumber()和ID添加回视图中，您可以很容易地从数据中确定您的原始键。但是-这不是应该提交到表中的东西，因为我相当确定视图的RowNumber()永远不会随着底层数据的改变而可靠地相同，即使使用OVER(ORDER BY ID ASC)来尝试和帮助它。

示例输出(从REF.View_Systems中选择UniqueId，ID，ROWNR，Name )：

UniqueId ID ROWNR Name 11 1 1 Amazon A 12 1 2 Amazon B 13 1 3 Amazon C 14 1 4 Amazon D 15 1 5 Amazon E

Table1：

[ID] [Name] 1 Amazon

Table2：

[ID] [Version] 1 A 1 B 1 C 1 D 1 E

CREATE VIEW [REF].[View_Systems]
AS    
SELECT 
CAST(CONCAT(CAST(TABA.[ID] AS VARCHAR(4)), 
        CAST(ROW_NUMBER() OVER(ORDER BY TABA.[ID] ASC) as VARCHAR(4)) 
        )  AS int) AS [UniqueId]
,TABA.[ID]
,ROW_NUMBER()  OVER(ORDER BY TABA.[ID] ASC) AS ROWNR
,TABA.[Name]  
FROM  [Ref].[Table1] TABA LEFT JOIN [Ref].[Table2] TABB ON TABA.[ID] = TABB.[ID]
GO