SQLi 101: Can you bypass the login page and get access to the admin account?
Union based SQLi: Can you expose all the data in the database?
SQLi with Insert: Can you insert any interesting records into the database?
SQLi with Order By: Can you infer information from the order?
SQLi with Multibyte Characters: Even addslashes won't save you!
Blind SQLi: Go to sleep when you are eye-masked.