I'm trying to test SQL injection on a site (PHP, uses MySQL Database). When I put an apostrophe in the username field and leave the password box blank, after submitting, the form reloads and the fields become empty again. But when I used an apostrophe in the password field, the message says "Invalid Username/password".
What does that indicate? And if I put admin' as username (don't add comments) and in the password field, write
;Drop Table users; (don't add comment) are my comments gonna work?