列忽略創建唯一索引

Question

給出一個觀點

CREATE VIEW MyView WITH SCHEMABINDING AS 
SELECT A, B, Year, t1.FKId, C, D, COUNT_BIG(*) as Cnt, SUM(W) As Wgt 
FROM [dbo].[T1] t1 
INNER JOIN [dbo].T2 t2 ON t1.FKId = t2.Id 
INNER JOIN [dbo].T3 t3 ON t1.FKId = t3.FKId AND t1.FKId = t3.FKId 
GROUP BY A, B, Year, t1.FKId, C, D 

當我試圖使該索引視圖

CREATE UNIQUE CLUSTERED INDEX IX_CLU_My 
ON MyView (FKId, A, B, Year, C, D) 

的SQL Server抱怨重複鍵，但錯誤消息只考慮5指定了6列：

CREATE UNIQUE INDEX語句終止，因爲找到了對象名稱'dbo的重複鍵.MyView'和索引名稱'IX_CLU_My'。重複鍵值是（934,1,6,2014,1）。

存在於對應於第一鍵4的視圖中的實際數據是：

FKId A B Year C D 
934 1 6 2014 1 5 
934 1 6 2014 1 15 
934 1 6 2014 2 5 
934 1 6 2014 3 5 

考慮到第一5列，該錯誤消息將是正確的。爲什麼第六列不考慮唯一性？

Answer 1

如果您可以添加HAVING子句並且沒有記錄返回，那麼我將幫助您進一步解決此問題。

SELECT A, B, Year, t1.FKId, C, D, COUNT_BIG(*) as Cnt 
FROM [dbo].[T1] t1 
INNER JOIN [dbo].T2 t2 ON t1.FKId = t2.Id 
INNER JOIN [dbo].T3 t3 ON t1.FKId = t3.FKId AND t1.FKId = t3.FKId 
GROUP BY A, B, Year, t1.FKId, C, D 
HAVING Count(*) > 1