Estou usando uma classe para fazer conexao com o banco,mas esta dando

<?php

/*------------------------------------------------------------------------------
** File: class.db.php
** Class: Simply MySQLi
** Description: PHP MySQLi wrapper class to handle common database queries and operations
** Version: 1.0
** Updated: 18-Feb-2013
** Author: Bennett Stone
** Homepage: www.phpdevtips.com
**------------------------------------------------------------------------------
** COPYRIGHT (c) 2012 - 2013 BENNETT STONE
**
** The source code included in this package is free software; you can
** redistribute it and/or modify it under the terms of the GNU General Public
** License as published by the Free Software Foundation. This license can be
** read at:
**
** [url="http://www.opensource.org/licenses/gpl-license.php"][http://www.opensource.org/licenses/gpl-license.php[/url]](http://www.opensource.org/licenses/gpl-license.php%5B/url%5D)
**
** This program is distributed in the hope that it will be useful, but WITHOUT
** ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
** FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
**------------------------------------------------------------------------------ */

define('DB_HOST', 'localhost' ); // set database host
define('DB_USER', 'root'); // set database user
define('DB_PASS', ''); // set database password
define('DB_NAME', 'projeto'); // set database name
define('SEND_ERRORS_TO', 'renanzdm@gmail.com' ); //set email notification email address
define('DISPLAY_DEBUG',true); //display db errors?
class DB
{

 private $link;
 public $filter;

 /**
 * Allow the class to send admins a message alerting them to errors
 * on production sites
 */
 public function log_db_errors( $error, $query, $severity )
 {
 $headers = 'MIME-Version: 1.0' . "\r\n";
 $headers .= 'Content-type: text/html; charset=UTF-8' . "\r\n";
 $headers .= 'To: Admin <'.SEND_ERRORS_TO.'>' . "\r\n";
 $headers .= 'From: Yoursite <system@your-site.com>' . "\r\n";

 $message = '<p>An error has occurred:</p>';

 $message .= '<p>Error at '. date('Y-m-d H:i:s').': ';
 $message .= 'Query: '. htmlentities( $query ).'<br />';
 $message .= '</p>';
 $message .= '<p>Severity: '. $severity .'</p>';

 mail( SEND_ERRORS_TO, 'Database Error', $message, $headers);

 if( DISPLAY_DEBUG )
 {
 echo $message;
 }
 }

public function __construct()

 global $connection;
mb_internal_encoding( 'UTF-8' );
mb_regex_encoding( 'UTF-8' );
$this->link = new mysqli( DB_HOST, DB_USER, DB_PASS, DB_NAME );

 if( mysqli_connect_errno() )
 {
 $this->log_db_errors( "Connect failed: %s\n", mysqli_connect_error(), 'Fatal' );
 exit();
 }
}

public function __destruct()

$this->disconnect();
}

/**
* Sanitize user data
*
* @access public
* @param string, array

 * @return string, array
 *
 */
 public function filter( $data )
 {
 if( !is_array( $data ) )
 {
 $data = trim( htmlentities( $data ) );
 $data = mysqli_real_escape_string( $this->link, $data );
 }
 else
 {
 //Self call function to sanitize array data
 $data = array_map( array( 'DB', 'filter' ), $data );
 }
 return $data;
 }

 /**
 * Determine if common non-encapsulated fields are being used
 *
 * @access public
 * @param string
 * @param array
 * @return bool
 *
 */
 public function db_common( $value = '' )
 {
 if( is_array( $value ) )
 {
 foreach( $value as $v )
 {
 if( preg_match( '/AES_DECRYPT/i', $v ) || preg_match( '/AES_ENCRYPT/i', $v ) || preg_match( '/now()/i', $v ) )
 {
 return true;
 }
 else
 {
 return false;
 }
 }
 }
 else
 {
 if( preg_match( '/AES_DECRYPT/i', $value ) || preg_match( '/AES_ENCRYPT/i', $value ) || preg_match( '/now()/i', $value ) )
 {
 return true;
 }
 }
 }

 /**
 * Perform queries
 * All following functions run through this function
 * All data run through this function is automatically sanitized using the filter function
 *
 * @access public
 * @param string
 * @return string
 * @return array
 * @return bool
 *
 */
 public function query( $query )
 {
 $query = $this->link->query( $query );
 if( mysqli_error( $this->link ) )
 {
 $this->log_db_errors( mysqli_error( $this->link ), $query, 'Fatal' );
 return false;
 }
 else
 {
 return true;
 }
 mysqli_free_result( $query );
 }

 /**
 * Determine if database table exists
 *
 * @access public
 * @param string
 * @return bool
 *
 */
 public function table_exists( $name )
 {
 $check = $this->link->query("SELECT * FROM '$name' LIMIT 1");
 if( $check )
 {
 return true;
 }
 else
 {
 return false;
 }
 mysqli_free_result( $check );
 }

 /**
 * Count number of rows found matching a specific query
 *
 * @access public
 * @param string
 * @return int
 *
 */
 public function num_rows( $query )
 {
 $query = $this->link->query( $query );
 if( mysqli_error( $this->link ) )
 {
 $this->log_db_errors( mysqli_error( $this->link ), $query, 'Fatal' );
 return mysqli_error( $this->link );
 }
 else
 {
 return mysqli_num_rows( $query );
 }
 mysqli_free_result( $query );
 }

 /**
 * Run check to see if value exists, returns true or false
 *
 * Example Usage:
 * $check_user = array(
 * 'user_email' => 'someuser@gmail.com',
 * 'user_id' => 48
 * );
 * $exists = exists( 'your_table', 'user_id', $check_user );
 *
 * @access public
 * @param string database table name
 * @param string field to check (i.e. 'user_id' or COUNT(user_id))
 * @param array column name => column value to match
 * @return bool
 *
 */
 public function exists( $table = '', $check_val = '', $params = array() )
 {
 if( empty($table) || empty($check_val) || empty($params) )
 {
 return false;
 exit;
 }
 $check = array();
 foreach( $params as $field => $value )
 {

 if( !empty( $field ) && !empty( $value ) )
 {
 //Check for frequently used mysql commands and prevent encapsulation of them
 if( $this->db_common( $value ) )
 {
 $check[] = "$field = $value";
 }
 else
 {
 $check[] = "$field = '$value'";
 }
 }

 }
 $check = implode(' AND ', $check);

 $rs_check = "SELECT $check_val FROM ".$table." WHERE $check";
 $number = $this->num_rows( $rs_check );
 if( $number === 0 )
 {
 return false;
 }
 else
 {
 return true;
 }
 exit;
 }

 /**
 * Return specific row based on db query
 *
 * @access public
 * @param string
 * @return array
 *
 */
 public function get_row( $query )
 {
 $query = $this->link->query( $query );
 if( mysqli_error( $this->link ) )
 {
 $this->log_db_errors( mysqli_error( $this->link ), $query, 'Fatal' );
 return false;
 }
 else
 {
 $r = mysqli_fetch_row( $query );
 mysqli_free_result( $query );
 return $r;
 }
 }

 /**
 * Perform query to retrieve array of associated results
 *
 * @access public
 * @param string
 * @return array
 *
 */
 public function get_results( $query )
 {
 $row = array();
 $query = $this->link->query( $query );
 if( mysqli_error( $this->link ) )
 {
 $this->log_db_errors( mysqli_error( $this->link ), $query, 'Fatal' );
 return false;
 }
 else
 {
 while( $r = mysqli_fetch_array( $query, MYSQLI_ASSOC ) )
 {
 $row[] = $r;
 }
 mysqli_free_result( $query );
 return $row;
 }
 }

 /**
 * Insert data into database table
 *
 * @access public
 * @param string table name
 * @param array table column => column value
 * @return bool
 *
 */
 public function insert( $table, $variables = array() )
 {

 $sql = "INSERT INTO ". $table;
 $fields = array();
 $values = array();
 foreach( $variables as $field => $value )
 {
 $fields[] = $field;
 $values[] = "'".$value."'";
 }
 $fields = ' (' . implode(', ', $fields) . ')';
 $values = '('. implode(', ', $values) .')';

 $sql .= $fields .' VALUES '. $values;

 $query = mysqli_query( $this->link, $sql );

 if( mysqli_error( $this->link ) )
 {
 //return false;
 $this->log_db_errors( mysqli_error( $this->link ), $sql, 'Fatal' );
 return false;
 }
 else
 {
 return true;
 }
 }

 /**
 * Insert data KNOWN TO BE SECURE into database table
 * Ensure that this function is only used with safe data
 * No class-side sanitizing is performed on values found to contain common sql commands
 * As dictated by the db_common function
 * All fields are assumed to be properly encapsulated before initiating this function
 *
 * @access public
 * @param string table name
 * @param array table column => column value
 * @return bool
 */
 public function insert_safe( $table, $variables = array() )
 {
 $sql = "INSERT INTO ". $table;
 $fields = array();
 $values = array();
 foreach( $variables as $field => $value )
 {
 $fields[] = $this->filter( $field );
 //Check for frequently used mysql commands and prevent encapsulation of them
 $values[] = $value;
 }
 $fields = ' (' . implode(', ', $fields) . ')';
 $values = '('. implode(', ', $values) .')';

 $sql .= $fields .' VALUES '. $values;
 $query = mysqli_query( $this->link, $sql );

 if( mysqli_error( $this->link ) )
 {
 $this->log_db_errors( mysqli_error( $this->link ), $sql, 'Fatal' );
 return false;
 }
 else
 {
 return true;
 }
 }

 /**
 * Update data in database table
 *
 * @access public
 * @param string table name
 * @param array values to update table column => column value
 * @param array where parameters table column => column value
 * @param int limit
 * @return bool
 *
 */
 public function update( $table, $variables = array(), $where = array(), $limit = '' )
 {

 $sql = "UPDATE ". $table ." SET ";
 foreach( $variables as $field => $value )
 {

 $updates[] = "`$field` = '$value'";
 }
 $sql .= implode(', ', $updates);

 foreach( $where as $field => $value )
 {
 $value = $value;

 $clause[] = "$field = '$value'";
 }
 $sql .= ' WHERE '. implode(' AND ', $clause);

 if( !empty( $limit ) )
 {
 $sql .= ' LIMIT '. $limit;
 }

 $query = mysqli_query( $this->link, $sql );

 if( mysqli_error( $this->link ) )
 {
 $this->log_db_errors( mysqli_error( $this->link ), $sql, 'Fatal' );
 return false;
 }
 else
 {
 return true;
 }
 }

 /**
 * Delete data from table
 *
 * @access public
 * @param string table name
 * @param array where parameters table column => column value
 * @param int max number of rows to remove.
 * @return bool
 *
 */
 public function delete( $table, $where = array(), $limit = '' )
 {
 $sql = "DELETE FROM ". $table;
 foreach( $where as $field => $value )
 {
 $value = $value;
 $clause[] = "$field = '$value'";
 }
 $sql .= " WHERE ". implode(' AND ', $clause);

 if( !empty( $limit ) )
 {
 $sql .= " LIMIT ". $limit;
 }

 $query = mysqli_query( $this->link, $sql );

 if( mysqli_error( $this->link ) )
 {
 //return false; //
 $this->log_db_errors( mysqli_error( $this->link ), $sql, 'Fatal' );
 return false;
 }
 else
 {
 return true;
 }
 }

 /**
 * Get last auto-incrementing ID associated with an insertion
 *
 * @access public
 * @param none
 * @return int
 *
 */
 public function lastid()
 {
 return mysqli_insert_id( $this->link );
 }

 /**
 * Get number of fields
 *
 * @access public
 * @param query
 * @return int
 */
 public function num_fields( $query )
 {
 $query = $this->link->query( $query );
 return mysqli_num_fields( $query );
 mysqli_free_result( $query );
 }

 /**
 * Get field names associated with a table
 *
 * @access public
 * @param query
 * @return array
 */
 public function list_fields( $query )
 {
 $query = $this->link->query( $query );
 return mysqli_fetch_fields( $query );
 mysqli_free_result( $query );
 }

 /**
 * Truncate entire tables
 *
 * @access public
 * @param array database table names
 * @return int number of tables truncated
 *
 */
 public function truncate( $tables = array() )
 {
 if( !empty($tables) )
 {
 $truncated = 0;
 foreach( $tables as $table )
 {
 $truncate = "TRUNCATE TABLE `".trim($table)."`";
 mysqli_query( $this->link, $truncate );
 if( !mysqli_error( $this->link ) )
 {
 $truncated++;
 }
 }
 return $truncated;
 }
 }

 /**
 * Output results of queries
 *
 * @access public
 * @param string variable
 * @param bool echo [true,false] defaults to true
 * @return string
 *
 */
 public function display( $variable, $echo = true )
 {
 $out = '';
 if( !is_array( $variable ) )
 {
 $out .= $variable;
 }
 else
 {
 $out .= '<pre>';
 $out .= print_r( $variable, TRUE );
 $out .= '</pre>';
 }
 if( $echo === true )
 {
 echo $out;
 }
 else
 {
 return $out;
 }
 }

 /**
 * Disconnect from db server
 * Called automatically from __destruct function
 */
 public function disconnect()
 {
mysqli_close( $this->link );
}

}

alguem poderia me ajudar estou tentando fazer uma paginção de resultados, mas para isso preciso usar mysql_query e acho q alguma função dessa classe esta conflitando alguem sabo o por qe ??