Error Message:
Msg 1941, Level 16, State 1, Line 2
Cannot create nonunique clustered index on view ‘%.*ls’ because only unique clustered indexes are allowed. Consider creating unique clustered index instead.
Severity level:
16.
Description:
This error message appears when you try to create a non-unique clustered index on a view.
Consequences:
The T-SQL statement can be parsed, but causes the error at runtime.
Resolution:
Error of the Severity Level 16 are generated by the user and can be fixed by the SQL Server user. The statement cannot be executed this way. Only unique clustered indexes can be created on a view.
Versions:
All versions of SQL Server (beginning with SQL Server 2000).
Example(s):
USE Northwind;
GO
SET NUMERIC_ROUNDABORT OFF;
SET ANSI_PADDING,
ANSI_WARNINGS,
CONCAT_NULL_YIELDS_NULL,
ARITHABORT,
QUOTED_IDENTIFIER,
ANSI_NULLS ON;
GO
IF OBJECT_ID (‘dbo.MyOrderView’, ‘View’) > 0
DROP VIEW dbo.MyOrderView;
GO
CREATE VIEW dbo.MyOrderView
WITH SCHEMABINDING
AS
SELECT SUM(UnitPrice*Quantity*(1.00-Discount)) AS Revenue,
OrderDate, ProductID, COUNT_BIG(*) AS MyCount
FROM dbo.[Order Details] AS od
JOIN dbo.Orders AS o
ON od.OrderID = o.OrderID
GROUP BY OrderDate, ProductID;
GO
CREATE CLUSTERED INDEX cix_MyOrderView
ON dbo.MyOrderView (OrderDate, ProductID);
GO
Remarks:
In the above example we try to create a non-unique clustered index on the view MyOrderView. This raises the error.