DBConnection

<?php

class DBConnection extends Mysqli
{
    protected $db;

    public function __construct()
    {
        global $config;
        $this->db = parent::__construct($config['dbhost'], $config['dbuser'], $config['dbpass'], $config['dbname']);
        if( $this->db->connect_errno )
        {
            die("Error database connection. ".$this->db->connect_error);
            exit;
        }
    }

    public function insert($table, $data)
    {
        if( is_array($data) )
        {
            $insert_data = "";
            foreach($data as $column => $value)
            {
                $insert_data .= $column."='".$this->db->real_escape_string($value)."' ";
            }
            $insert_data = trim($insert_data);

            if( $insert_data !== "" )
            {
                $qry = "INSERT INTO $table SET $insert_data";
                $a = $this->db->query($qry) or die("Insert query error. ".$this->db->error);
                return $a;
            }
        }
        else
        {
            return "Insert query error. Inserted data must be in array";
            exit;
        }
    }

    public function __destruct()
    {
        $this->db->close();
    }
}

?>