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copied!<p>Sounds like you're trying to let users know whether a username or email already exists at registration time. Here's what you can do:</p> <pre><code><?php //---------------------------------------- // Create first query $usernameQuery = 'SELECT username FROM users WHERE username="'.mysql_real_escape_string($username).'"'; //---------------------------------------- // Query db $usernameResult = mysql_query($userNameQuery); //---------------------------------------- // Check if result is empty if(mysql_num_rows($usernameResult) > 0){ //---------------------------------------- // Username already exists $error[] = 'Username already exists'; //---------------------------------------- // Return error to user and stop execution // of additional queries/code } else { //---------------------------------------- // Check if email exists //---------------------------------------- // Create query $emailQuery = 'SELECT email FROM users WHERE email="'.mysql_real_escape_string($email).'"'; //---------------------------------------- // Query the db $emailResult = mysql_query($emailQuery); //---------------------------------------- // Check if the result is empty if(mysql_num_rows($emailResult) > 0){ //---------------------------------------- // Email already exists $error[] = 'Email already exists'; //---------------------------------------- // Return error to user and stop execution // of additional queries/code } else { //---------------------------------------- // Continue with registration... } } ?> </code></pre> <p>Please note that you should always escape your values before executing the actual query.</p> <p>Additional Resources:<br /> <a href="http://us.php.net/manual/en/function.mysql-real-escape-string.php" rel="nofollow">http://us.php.net/manual/en/function.mysql-real-escape-string.php</a> http://us.php.net/manual/en/function.mysql-escape-string.php</p>

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