Query doesnt give a value?

[tom232]

why am i not getting a value for $result
[i]
$result = mysql_query(" select * from user where username='$username' ");
  if (!$result)
    throw new Exception('Could not execute query');[/i]
[b]THE CODE[/b]
[code]<?php

require_once('db_fns.php');

function register($username, $email, $password)
// register new person with db
// return true or error message
{
  // connect to db
  $conn = mysql_connect(localhost, collegenote, OC1kl07r);
 
  // check if username is unique
  $result = mysql_query(" select * from user where username='$username' ");
  if (!$result)
    throw new Exception('Could not execute query');
  if ($result->num_rows>0)
    throw new Exception('That username is taken - go back and choose another one.');


  // if ok, put in db
  $result = mysql_query("insert into user values
                        ('$username', sha1('$password'), '$email')");
  if (!$result)
    throw new Exception('Could not register you in database - please try again later.');

  return true;
}

function login($username, $password)
// check username and password with db
// if yes, return true
// else throw exception
{
  // connect to db
  $conn = db_connect();

  // check if username is unique
  $result = $conn->query("select * from user
                        where username='$username'
                        and passwd = sha1('$password')");
  if (!$result)
    throw new Exception('Could not log you in.');
 
  if ($result->num_rows>0)
    return true;
  else
    throw new Exception('Could not log you in.');
}

function check_valid_user()
// see if somebody is logged in and notify them if not
{
  if (isset($_SESSION['valid_user']))
  {
      echo 'Logged in as '.$_SESSION['valid_user'].'.';
      echo '<br />';
  }
  else
  {
    // they are not logged in
    do_html_heading('Problem:');
    echo 'You are not logged in.<br />';
    do_html_url('login.php', 'Login');
    do_html_footer();
    exit;
  } 
}

function change_password($username, $old_password, $new_password)
// change password for username/old_password to new_password
// return true or false
{
  // if the old password is right
  // change their password to new_password and return true
  // else throw an exception
  login($username, $old_password);
  $conn = db_connect();
  $result = $conn->query( "update user
                            set passwd = sha1('$new_password')
                            where username = '$username'");
  if (!$result)
    throw new Exception('Password could not be changed.');
  else
    return true;  // changed successfully
}

function get_random_word($min_length, $max_length)
// grab a random word from dictionary between the two lengths
// and return it
{
  // generate a random word
  $word = '';
  // remember to change this path to suit your system
  $dictionary = '/usr/dict/words';  // the ispell dictionary
  $fp = @fopen($dictionary, 'r');
  if(!$fp)
    return false;
  $size = filesize($dictionary);

  // go to a random location in dictionary
  srand ((double) microtime() * 1000000);
  $rand_location = rand(0, $size);
  fseek($fp, $rand_location);

  // get the next whole word of the right length in the file
  while (strlen($word)< $min_length || strlen($word)>$max_length || strstr($word, "'"))
  { 
    if (feof($fp)) 
        fseek($fp, 0);        // if at end, go to start
    $word = fgets($fp, 80);  // skip first word as it could be partial
    $word = fgets($fp, 80);  // the potential password
  };
  $word=trim($word); // trim the trailing \n from fgets
  return $word; 
}

function reset_password($username)
// set password for username to a random value
// return the new password or false on failure
{
  // get a random dictionary word b/w 6 and 13 chars in length
  $new_password = get_random_word(6, 13);
 
  if($new_password==false)
    throw new Exception('Could not generate new password.');
  // add a number  between 0 and 999 to it
  // to make it a slightly better password
  srand ((double) microtime() * 1000000);
  $rand_number = rand(0, 999);
  $new_password .= $rand_number;

  // set user's password to this in database or return false
  $conn = db_connect();
  $result = $conn->query( "update user
                          set passwd = sha1('$new_password')
                          where username = '$username'");
  if (!$result)
    throw new Exception('Could not change password.');  // not changed
  else
    return $new_password;  // changed successfully 
}

function notify_password($username, $password)
// notify the user that their password has been changed
{
    $conn = db_connect();
    $result = $conn->query("select email from user
                            where username='$username'");
    if (!$result)
    {
      throw new Exception('Could not find email address.'); 
    }
    else if ($result->num_rows==0)
    {
      throw new Exception('Could not find email address.');  // username not in db
    }
    else
    {
      $row = $result->fetch_object();
      $email = $row->email;
      $from = "From: support@phpbookmark \r\n";
      $mesg = "Your PHPBookmark password has been changed to $password \r\n"
              ."Please change it next time you log in. \r\n";
     
     
      if (mail($email, 'PHPBookmark login information', $mesg, $from))
        return true;     
      else
        throw new Exception('Could not send email.');
    }
}

?>
[/code]

[btherl]

What happens when you run your code, and what are you expecting to happen?

[PFMaBiSmAd]

There are a number of problems -

1) The mysql_connect(...) function expects quoted strings as parameters and is probably failing, which your code does not know as you are not checking the status returned by the function call.

2) You are not selecting a database [b]mysql_select_db(...)[/b] which will cause the mysql_query(...) fail.

3) You are not displaying the [b]mysql_error()[/b] returned when the mysql_query(...) fails to display the reason that the query failed.