[SOLVED] php/mysql checking for duplicates in database

[laron]

Hey,

quick question(hopefully), how can i check for duplicates in a database.  For instance, checking for already registered users, etc.

 

thanks

[btherl]

If checking if a new user has the same name as an old user, something like this is enough:

 

$sql = "SELECT * FROM users WHERE username = '$new_user'";
$result = mysql_query($sql) or die(mysql_error());
if (mysql_num_rows($result) > 0) {
  print "$new_user already exists!\n";
} else {
  print "$new_user really is new!\n";
}

[laron]

i get an error that says query was empty.

[john010117]

Did you change the table names and the variable names to what you have? Also, is there any records in the db?

[laron]

yes for both questions

[btherl]

Please post your code

[laron]

nevermind, figured it out... thanks for the code(i made some errors changing it to fit my database)

 

thanks and solved