did I miss something ???

or there are more than 2 failures ...

select db_id('dbdb')

-- and the second one

select object_id('dbdb')

I don't think it will return the same value for a database.

I dig a little bit on the Object_id for a reference .. and in msdn

http://msdn.microsoft.com/en-us/library/ms190328.aspx

it says

It would return NULL ..

so the query

USE master;

GO

IF OBJECT_ID('DBDB') IS NULL CREATE DATABASE DBDB

-- it should be IF DB_ID('DBDB') IS NULL CREATE DATABASE DBDB

GO

it would fail, if the database already exist..

EDIT : Okay, in the question , the first query drops the database .. so , it would be fine in this Qotd , but in general.. I think it would be an information while using it in the code..