check if username exists problem

zevacronet

hi, i'm trying create a login page for my site and at this point i'm trying to write code so it doesn't let people create duplicates. The only problem im having is checkin the database to see if their's a duplicate listing. I dont know why this is so hard for me, i did just come back from vacation so i must be a little rusty. Any help would be appreciated. When i run the script i just get a blank page and it doesn't give me any errors. I commented out the code that checks for duplicates and it works. here it is:

<?php

// Check to see if user already exsists

include ("../connect.php");

$query = "SELECT * FROM members WHERE username ='$username'";
$result = @($query) or die("Couldn't execute query.");

if(mysql_num_rows($result) > 0) {
echo "Name already exists.";
echo "Please go back and choose another one.";
echo " <a href=\"javascript:history.back()\">Back</a>";
}

// Performing SQL query

$query2 = "INSERT into members (first_name, last_name, city, state, email, username, password, phint, specials, membersince)
VALUES ('".$first_name."', '".$last_name."', '".$city."', '".$state."', '".$email."', '".$username."', '".$password."', '".$phint."', '".$specials."', 'a')";

$result2 = @($query2) or die("Couldn't execute query.");

include("../headerinc.php");
echo " ;
echo "Your account was created successfully! ";
echo "You will receive a confirmation e-mail shortly to activate your account.";
mysql_close();
?>

Anon

could it be the @ symbols --> i don't recall using those for mysql

bastien

Anon

I don't see any error in your code.

You can try and pre-process the data from the form, maybe trim(). Otherwise, it may be that you have the table column names or form INPUT field name wrong.

If non of that works, create a new mysql table, and a new web form, and try again.

Richie.
geocities.com/akindele/

Anon

Even if the duplicate check finds a problem you still try to execute the insert; you should have the insert in an "else" clause to the "if".

But that shouldn't cause a blank page. I'd get rid of the '@' signs and add a call to mysql_error() in the "die" statements.

zevacronet

it has to be my if statement because i've tried to see if the duplicate name code would work by itself and it did. I tried the inserting a name code and that worked. It just wont work together. I know it has to be the IF statement. All im trying to do is when it's processed, check for a duplicate if not, run the rest of the script. If it is, dont process the rest of the script and tell the user to go back. thanks for the help guys

saltwater

There is a much cleaner way of doing this ... give the field username a UNIQUE flag, and do an insert query. then check if there was a record inserted with mysql_affected_rows, if this return 0, the user already exists, if 1, the user didn't exists but it does now 🙂