Blind SQLi
Unlike In-Band SQL injection, where we can see the results of our attack directly on the screen, blind SQLi is when we get little to no feedback to confirm whether our injected queries were, in fact, successful or not, this is because the error messages have been disabled, but the injection still works regardless. It might surprise you that all we need is that little bit of feedback to successfully enumerate a whole database.
One of the most straightforward Blind SQL Injection techniques is when bypassing authentication methods such as login forms. In this instance, we aren't that interested in retrieving data from the database; We just want to get past the login.
And example is ' OR 1=1;— or ‘ OR 1=1# into a input section for user name and password.