Because DDL triggers are not schema-scoped and, therefore do not appear in the sys. Objects catalog view, the OBJECT_ID function cannot be used to query whether they exist in the database.

• 因为DDL触发器不在架构范围内；所以不会在sys.；objects目录视图中出现；无法使用OBJECT_ID函数来查询数据库中是否存在DDL触发器。