Test on two databases - one that has case-sensitive string comparision (most of DB) and one that does not - it would probably be Mysql with some screwed collation, see in the comments below. Windows databases may ignore case too (I'm not sure). Create course, set shortname and idnumber Create another course, while creating make sure you can not create the course with the same shortname and idnumber Update one of the courses, make sure you can not change shortname or idnumber to whatever is already used in another course Update course changing the case of shortname/idnumber, make sure it is possible. Create course with the same shortname/idnumber as existing but with different case. Should be possible on normal database and not possible on mysql with wrong collation (and probably some windows db)