MySQL Loop

[Mockers]

Hi...first day w/ php

 

Ive connected to my mysql db, and now i need to loop through it or use some other method in order to find out if a username has already been used or not.

[only one]

for registering????

<?php
$query= mysql_query("SELECT user FROM users WHERE user='$user'");
$check = mysql_num_rows($query);
if ($check>0) {
echo "already in use";
}else{
lets the through...
}
?>

[Mockers]

I dont quite understand.

 

What does mysql_num_rows() do?

 

nvm i get it lol

[per1os]

Returns the number of rows that the query returned. If it returned more than 1 row, there is a user with the name of $user in the database. Therefore if the number of rows the query returned is greater than 0 that username exists in the database.

[only one]

it counts how many rows has that username

then if there more than 0 rows it doesnt let it through....