Listing 1: Validating Database and Object IDs Before Referencing the Function
DECLARE @db_id smallint;
DECLARE @object_id int;

SET @db_id = DB_ID(N'AdventureWorks');
SET @object_id = OBJECT_ID(N'AdventureWorks.Person.Address');

IF @db_id IS NULL
BEGIN;
    PRINT N'Invalid database';
END;
ELSE IF @object_id IS NULL
BEGIN;
    PRINT N'Invalid object';
END;

SELECT * FROM sys.dm_db_index_physical_stats (@db_id, @object_id, NULL, NULL,  NULL)