Hi Everyone,

I am a beginner in PHP and would need your help with this. I get this problem:

Warning: mysql_numrows(): supplied argument is not a valid MySQL result resource in database.php on line 207

Here is my code:

include("constants.php");

class MySQLDB
{
   var $connection;         //The MySQL database connection
   var $num_active_users;   //Number of active users viewing site
   var $num_active_guests;  //Number of active guests viewing site
   var $num_members;        //Number of signed-up users
   /* Note: call getNumMembers() to access $num_members! */

   /* Class constructor */
   function MySQLDB(){
      /* Make connection to database */
      $this->connection = mysql_connect(DB_SERVER, DB_USER, DB_PASS) or die(mysql_error());
      mysql_select_db(DB_NAME, $this->connection) or die(mysql_error());

      /**
       * Only query database to find out number of members
       * when getNumMembers() is called for the first time,
       * until then, default value set.
       */
      $this->num_members = -1;

      if(TRACK_VISITORS){
         /* Calculate number of users at site */
         $this->calcNumActiveUsers();

         /* Calculate number of guests at site */
         $this->calcNumActiveGuests();
      }
   }

   /**
    * confirmUserPass - Checks whether or not the given
    * username is in the database, if so it checks if the
    * given password is the same password in the database
    * for that user. If the user doesn't exist or if the
    * passwords don't match up, it returns an error code
    * (1 or 2). On success it returns 0.
    */
   function confirmUserPass($username, $password){
      /* Add slashes if necessary (for query) */
      if(!get_magic_quotes_gpc()) {
          $username = addslashes($username);
      }

      /* Verify that user is in database */
      $q = "SELECT password FROM ".TBL_USERS." WHERE username = '$username'";
      $result = mysql_query($q, $this->connection);
      if(!$result || (mysql_numrows($result) < 1)){
         return 1; //Indicates username failure
      }

      /* Retrieve password from result, strip slashes */
      $dbarray = mysql_fetch_array($result);
      $dbarray['password'] = stripslashes($dbarray['password']);
      $password = stripslashes($password);

      /* Validate that password is correct */
      if($password == $dbarray['password']){
         return 0; //Success! Username and password confirmed
      }
      else{
         return 2; //Indicates password failure
      }
   }

   /**
    * confirmUserID - Checks whether or not the given
    * username is in the database, if so it checks if the
    * given userid is the same userid in the database
    * for that user. If the user doesn't exist or if the
    * userids don't match up, it returns an error code
    * (1 or 2). On success it returns 0.
    */
   function confirmUserID($username, $userid){
      /* Add slashes if necessary (for query) */
      if(!get_magic_quotes_gpc()) {
          $username = addslashes($username);
      }

      /* Verify that user is in database */
      $q = "SELECT userid FROM ".TBL_USERS." WHERE username = '$username'";
      $result = mysql_query($q, $this->connection);
      if(!$result || (mysql_numrows($result) < 1)){
         return 1; //Indicates username failure
      }

      /* Retrieve userid from result, strip slashes */
      $dbarray = mysql_fetch_array($result);
      $dbarray['userid'] = stripslashes($dbarray['userid']);
      $userid = stripslashes($userid);

      /* Validate that userid is correct */
      if($userid == $dbarray['userid']){
         return 0; //Success! Username and userid confirmed
      }
      else{
         return 2; //Indicates userid invalid
      }
   }

   /**
    * usernameTaken - Returns true if the username has
    * been taken by another user, false otherwise.
    */
   function usernameTaken($username){
      if(!get_magic_quotes_gpc()){
         $username = addslashes($username);
      }
      $q = "SELECT username FROM ".TBL_USERS." WHERE username = '$username'";
      $result = mysql_query($q, $this->connection);
      return (mysql_numrows($result) > 0);
   }

   /**
    * usernameBanned - Returns true if the username has
    * been banned by the administrator.
    */
   function usernameBanned($username){
      if(!get_magic_quotes_gpc()){
         $username = addslashes($username);
      }
      $q = "SELECT username FROM ".TBL_BANNED_USERS." WHERE username = '$username'";
      $result = mysql_query($q, $this->connection);
      return (mysql_numrows($result) > 0);
   }

   /**
    * addNewUser - Inserts the given (username, password, email)
    * info into the database. Appropriate user level is set.
    * Returns true on success, false otherwise.
    */
   function addNewUser($username, $password, $email){
      $time = time();
      /* If admin sign up, give admin user level */
      if(strcasecmp($username, ADMIN_NAME) == 0){
         $ulevel = ADMIN_LEVEL;
      }else{
         $ulevel = USER_LEVEL;
      }
      $q = "INSERT INTO ".TBL_USERS." VALUES ('$username', '$password', '0', $ulevel, '$email', $time)";
      return mysql_query($q, $this->connection);
   }

   /**
    * updateUserField - Updates a field, specified by the field
    * parameter, in the user's row of the database.
    */
   function updateUserField($username, $field, $value){
      $q = "UPDATE ".TBL_USERS." SET ".$field." = '$value' WHERE username = '$username'";
      return mysql_query($q, $this->connection);
   }

   /**
    * getUserInfo - Returns the result array from a mysql
    * query asking for all information stored regarding
    * the given username. If query fails, NULL is returned.
    */
   function getUserInfo($username){
      $q = "SELECT * FROM ".TBL_USERS." WHERE username = '$username'";
      $result = mysql_query($q, $this->connection);
      /* Error occurred, return given name by default */
      if(!$result || (mysql_numrows($result) < 1)){
         return NULL;
      }
      /* Return result array */
      $dbarray = mysql_fetch_array($result);
      return $dbarray;
   }

   /**
    * getNumMembers - Returns the number of signed-up users
    * of the website, banned members not included. The first
    * time the function is called on page load, the database
    * is queried, on subsequent calls, the stored result
    * is returned. This is to improve efficiency, effectively
    * not querying the database when no call is made.
    */
   function getNumMembers(){
      if($this->num_members < 0){
         $q = "SELECT * FROM ".TBL_USERS;
         $result = mysql_query($q, $this->connection);
         $this->num_members = mysql_numrows($result);
      }
      return $this->num_members;
   }

   /**
    * calcNumActiveUsers - Finds out how many active users
    * are viewing site and sets class variable accordingly.
    */
   function calcNumActiveUsers(){
      /* Calculate number of users at site */
      $q = "SELECT * FROM ".TBL_ACTIVE_USERS;
      $result = mysql_query($q, $this->connection);
      $this->num_active_users = mysql_numrows($result);
   }

   /**
    * calcNumActiveGuests - Finds out how many active guests
    * are viewing site and sets class variable accordingly.
    */
   function calcNumActiveGuests(){
      /* Calculate number of guests at site */
      $q = "SELECT * FROM ".TBL_ACTIVE_GUESTS;
      $result = mysql_query($q, $this->connection);
      $this->num_active_guests = mysql_numrows($result);
   }

   /**
    * addActiveUser - Updates username's last active timestamp
    * in the database, and also adds him to the table of
    * active users, or updates timestamp if already there.
    */
   function addActiveUser($username, $time){
      $q = "UPDATE ".TBL_USERS." SET timestamp = '$time' WHERE username = '$username'";
      mysql_query($q, $this->connection);

      if(!TRACK_VISITORS) return;
      $q = "REPLACE INTO ".TBL_ACTIVE_USERS." VALUES ('$username', '$time')";
      mysql_query($q, $this->connection);
      $this->calcNumActiveUsers();
   }

   /* addActiveGuest - Adds guest to active guests table */
   function addActiveGuest($ip, $time){
      if(!TRACK_VISITORS) return;
      $q = "REPLACE INTO ".TBL_ACTIVE_GUESTS." VALUES ('$ip', '$time')";
      mysql_query($q, $this->connection);
      $this->calcNumActiveGuests();
   }

   /* These functions are self explanatory, no need for comments */

   /* removeActiveUser */
   function removeActiveUser($username){
      if(!TRACK_VISITORS) return;
      $q = "DELETE FROM ".TBL_ACTIVE_USERS." WHERE username = '$username'";

I already tried searching it on Google but I can't really get where actually is the problem here. Please help me.

Thanks!

Most likely an error with the SQL query on line 206. Output the query and test it in the MySQL console or PHP MyAdmin.

on line 206 you have a constant " TBL_ACTIVE_GUESTS " you need to check and see if it is not empty. That is the most likely cause of your trouble

Erm.. all isntances of mysql_numrows should be mysql_num_rows() <-notice the extra underscore

Line 50, 85, 113, 126, 164.... that should get you started... I saw a few more below it, as well.. 184, 197... there's more.