$sql

PHP:

1. <?php
2. // connecting to database...
3.  
4. $user = 'Login';
5. $qr = mysql_query('SELECT COUNT(*) FROM logins WHERE login="' . mysql_escape_string($user) . '"') or die(mysql_error());
6. $row = mysql_fetch_row($qr);
7. mysql_free_result($qr);
8. if (1 == $row[0]) print 'User exists';
9. else print 'User doesn\'t exist';
10. ?>

 

Я обычно так делаю:

PHP:

1. <?php
2. // connecting to database...
3.  
4. $user = 'Login';
5. $qr = mysql_query('SELECT * FROM logins WHERE login="' . mysql_escape_string($user) . '"') or die(mysql_error());
6. $row = mysql_fetch_row($qr);
7. mysql_free_result($qr);
8. if ($row['login'] == $user) print 'User exists';
9. else print 'User doesn\'t exist';
10. ?>
11.  

 

+1

и пора читать ман по sql!