Check if username already exists in database MySQL PHP

Question

I have a registration.php page I made and I need to check if a username is already in my database so that I won\'t have 2 members with the same name...

Here is how I

Answer 1

You can make the username field in the database a primary key or unique, which guarantees the username uniqueness in the database.

Then, if you try to insert an already existing username the mysql_query() function will fail, returning FALSE.

Besides that, you should always query the database for the existence of the username, using a simple select statement:

SELECT username FROM table WHERE username='$php_username_var';