Generic Class Wrapper

Link: http://us2.php.net/manual/en/language.oop5.php

The objective of this wrapper is to provide a streamlined interface to data stored in a database.

Notes

  • Object properties are stored in an array. This makes managing them must easier. Upon instantiation, the array is loaded with empty strings.
  • Magic methods are used to set and return properties.
  • The properties have a one-to-one, exact mapping to the underlying database.
  • A generic object exists beneath the specific object. It accepts a table name, identifier column name, and an array of values.

item.class.php

PHP:

<?php
/*mysql> show full columns from items;
+---------+------------------+-----------------+------+-----+---------+----------------+---------------------------------+---------+
| Field   | Type             | Collation       | Null | Key | Default | Extra          | Privileges                      | Comment |
+---------+------------------+-----------------+------+-----+---------+----------------+---------------------------------+---------+
| item_id | int(10) unsigned | NULL            |      | PRI | NULL    | auto_increment | select,insert,update,references |         |
| name    | varchar(64)      | utf8_unicode_ci |      |     |         |                | select,insert,update,references |         |
| url     | varchar(128)     | utf8_unicode_ci |      | MUL |         |                | select,insert,update,references |         |
| text    | text             | utf8_unicode_ci |      |     |         |                | select,insert,update,references |         |
+---------+------------------+-----------------+------+-----+---------+----------------+---------------------------------+---------+
4 rows in set (0.02 sec)
*/
 
require_once 'obj.class.php';
Class Item Extends Obj
{
        private $aData;
 
        public function __construct()
        {
                $this->aData=array_fill_keys(array('item_id','name','url','text'),'');
                parent::__construct();
        }
 
        public function __set($name, $value)
        {
                $this->aData[$name] = $value;
        }
 
        public function __get($name)
        {
                if (array_key_exists($name, $this->aData))
                        return $this->aData[$name];
        }
 
        public function load($id)
        {
                $this->aData=parent::load('items','item_id',$id);
        }
 
        public function save()
        {
                return parent::save('items','item_id',$this->aData);
        }
}
 
?>

obj.class.php

PHP:

<?php
require_once 'db.class.php';
 
Class Obj
{
        private $db;
 
        public function __construct()
        {
                $this->db=Database::singleton();
        }
 
        protected function load($sTable,$sIdName,$sId)
        {
                $aResult=false;
                $sQuery='SELECT * FROM `'.$sTable.'` WHERE `'.$sIdName.'`=\''.$this->db->SQLescape($sId).'\'';
                $this->db->query($sQuery);
                $aResult=$this->db->fetch_assoc();
                $this->db->free_result();
                return $aResult;
        }
 
        protected function save($sTable,$sIdName,$aArgs)
        {
                $sWhere=' WHERE `'.$sIdName.'`=\''.$this->db->SQLescape($aArgs[$sIdName]).'\'';
                unset($aArgs[$sIdName]);
                $sSet=$this->db->sPair($aArgs);
                $sQuery='SELECT * FROM `'.$sTable.'`'.$sWhere;
                $this->db->query($sQuery);
                if ($this->db->num_rows()>0)
                        $sQuery='UPDATE `'.$sTable.'` SET '.$sSet.$sWhere;
                else
                        $sQuery='INSERT INTO `'.$sTable.'` SET '.$sSet;
                $this->db->free_result();
                return $this->db->query($sQuery);
        }
 
        protected function remove($sTable,$sIdName,$sId)
        {
                $sQuery='DELETE FROM `'.$sTable.'` WHERE `'.$sIdName.'`=\''.$this->db->SQLescape($sId).'\'';
                return $this->db->query($sQuery);
        }
 
        public function __destruct()
        {
        }
}
?>

A search function will be added.

db.class.php

PHP:

<?php
Class Database
{
        private static $instance;
 
        private $rLink;
        private $db;
        private $ini;
        private $rResult;
 
        public function __construct()
        {
                $this->ini = parse_ini_file('config.ini.php','true');
                $this->rLink = mysql_connect
                                ($this->ini['db']['host'],
                                 $this->ini['db']['user'],
                                 $this->ini['db']['password']);
                if ($this->rLink === false)
                        trigger_error(mysql_error());
                $this->db = mysql_select_db ($this->ini['db']['database'],$this->rLink);
                if ($this->db === false)
                        trigger_error(mysql_error());
                return true;
        }
 
        public static function singleton()
        {
                if (!isset(self::$instance)) {
                        $c = __CLASS__;
                        self::$instance = new $c;
                }
                return self::$instance;
        }
 
        public function SQLescape($s)
        {
                return mysql_real_escape_string($s,$this->rLink);
        }
 
        public function host_information()
        {
                return mysql_get_host_info($this->rLink);
        }
 
        public function query($sQuery)
        {
                $this->rResult=mysql_query($sQuery,$this->rLink);
                if ($this->rResult === false)
                        trigger_error(mysql_error());
                return $this->rResult;
        }
 
        public function fetch_assoc()
        {
                return mysql_fetch_assoc($this->rResult);
        }
 
        public function sPair($aPair)
        {
                $sReturn='';
                foreach ($aPair as $k => $v)
                        $sReturn .= "`$k`='".$this->SQLescape($v).'\', ';
                $sReturn=substr($sReturn,0,-2);
                return $sReturn;
        }
 
        public function sWhere($aWhere)
        {
                $sReturn='';
                foreach ($aWhere as $k => $v)
                        $sReturn .= " `$k`='".$this->SQLescape($v).'\' AND ';
                return substr($sReturn,0,-4);
        }
 
        public function sRegExp($aRegExp)
        {
                $sReturn='';
                foreach ($aRegExp as $k => $v)
                        $sReturn .= " `$k` REGEXP '".$this->SQLescape($v).'\' AND ';
                return substr($sReturn,0,-4);
        }
 
        public function num_rows()
        {
                return mysql_num_rows($this->rResult);
        }
 
        public function free_result()
        {
                mysql_free_result($this->rResult);
        }
 
        public function __destruct()
        {
                if (isset($this->rLink))
                        if ($this->rLink !== false)
                                mysql_close($this->rLink);
        }
 
        public function __clone()
        {
                trigger_error('Clone is not allowed.', E_USER_ERROR);
        }
 
}
?>
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