Error Message:
Msg 2501, Level 16, State 45, Line 1
The CONCAT_NULL_YIELDS_NULL option must be set to ON to run DBCC CHECKCONSTRAINTS.
Severity level:
16.
Description:
This error message appears when you try to use the DBCC CHECKCONSTRAINTS command while the CONCAT_NULL_YIELDS_NULL option is deactivated.
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. The CONCAT_NULL_YIELDS_NULL must be set to ON before DBCC CHECKCONSTRAINTS can be used.
Versions:
This error message was introduced with SQL Server 2005.
Example(s):
USE tempdb;
GO
IF OBJECT_ID(‘tempdb..t’) > 0
DROP TABLE t
GO
CREATE TABLE t
(
id INT
)
GO
INSERT INTO t VALUES (100);
ALTER TABLE t WITH NOCHECK ADD
CONSTRAINT CHK_t_id CHECK (id > 100);
SET CONCAT_NULL_YIELDS_NULL OFF
DBCC CHECKCONSTRAINTS(‘t’);
GO
Remarks:
In the above example we try to execute DBCC CHECKCONSTRAINTS while the CONCAT_NULL_YIELDS_NULL option is deactivated. This raises the error.