Basically I have a user signup/login system on a MySQL backend. However, visitors can sign up multiple times with the same username. How would I get MySQL to check if there already exists the username in the database?
The table is like this
id username password email
1 blahblahb blahblah blah@blah.com
The table is like this
id username password email
1 blahblahb blahblah blah@blah.com