<?php

namespace Database;

/**
 * Description of PDO
 * @author stump
 */

require_once 'config.inc.php';

class PDO 
{
    public $pdo;
    public $statement;
    
    function __construct() 
    {
        $this -> connect();
    }
    
    public function connect()
    {
        $this -> pdo = new \PDO(
                "mysql:host=" . DB_HOST . " ;dbname=" . DB_NAME . ";", 
                DB_USER, 
                DB_PW
            );
        return $this -> pdo;
    }
    
    public function error()
    {
        if ( $this -> pdo -> errorCode() != '00000' )
        {
            throw new \Exception( implode( " ", $this -> pdo -> errorInfo() ) );
        }
        
        return TRUE;
    }

    public function prepare( $sql )
    {
        return empty( $this -> pdo )
            ? "Run without pdo connetcion"
            : ( $this -> statement = $this -> pdo -> prepare( $sql ) );
    }
    
    public function execute( $param )
    {
        return empty( $this -> statement )
            ? "Run without pdo connetcion"
            : empty( $param )
                ? $this -> statement -> execute()
                : $this -> statement -> execute( $param );
    }
    
    public function fetch()
    {
        return empty( $this -> statement )
            ? "Run without pdo connetcion"
            : $this -> statement -> fetchAll( \PDO::FETCH_CLASS );        
    }
}

<?php
define('DB_HOST', '127.0.0.1');
define('DB_USER', 'root');
define('DB_PW', '1111');
define('DB_NAME', 'mydb');

<?php

namespace Database;
use Database\QueryBuilder;

/**
 * Description of User
 * @author stump
 */
class Database
{
    public $pdo;
    
    public $sql = NULL;
    public $param = [];
            
    private $Query;    
    
    public function __construct()
    {
        $this -> pdo = new PDO();
    }
    
    public function Build()
    {
        $this -> Query = new QueryBuilder();
        return $this -> Query;
    }
    
    public function apply( QueryBuilder $Query )
    {
        $this -> sql = empty( $Query -> apply() ) 
                        ? ""
                        : $Query -> sql;
        return $this -> sql;
    }
    
    public function execute()
    {
        $this -> pdo -> prepare( $this -> sql );
        $execute = $this -> pdo -> execute( $this -> param );
        $this -> pdo -> error();
        return $execute;
    }
    
    public function query()
    {    
        $this -> pdo -> prepare( $this -> sql );
        $this -> pdo -> execute( $this -> param );
        $this -> pdo -> error();
        $fetch = $this -> pdo -> fetch();
        return $fetch;
    }
}

<?php

namespace Database;

/**
 * Description of QueryBuilder
 * @author stump
 */
class QueryBuilder 
{
    public $sql;
    public $field = [];
    
    private static $Instance;
    
    private $key_exclude = ["FIELD"];
    
    function __construct() 
    {
        static :: $Instance = $this;
    }
    
    public function addpart( $key, $value = "" )
    {
        $this -> field[ $key ][] = is_object( $value ) 
                                    ? array_keys( get_object_vars( $value ) ) 
                                    : ( array )$value;
        return static::$Instance;
    }
    
    public function apply()
    {
        $fields = [];
        foreach ( $this -> field as $key => $field )
        {
            foreach ( $field as $_field )
            {
                $fields[ $key ] =  " " . $key . " ";
                $fields[ $key ] .= $this -> prepare( $key, $_field );
            }
        }
        
        $this -> sql .= implode( " ", $fields );
        $this -> sql = str_replace( $this -> key_exclude, "", $this -> sql );
        
        return ( TRUE == $this -> sql );
    }
    
    private function prepare( $key, array $array )
    {
        $query = "";
        switch ($key)
        {
            case 'FIELD':
            case 'VALUES':
                $query .= "(" . implode( " , ", $array ) . ")";
                break;
            case 'JOIN':
            case 'INNER JOIN':
            case 'LEFT JOIN':
            case 'RIGHT JOIN':
            case 'CROSS JOIN':
                $query .= implode( " ON ", $array );
                break;
            case 'WHERE':
                $query .= implode( " AND ", $array );
                break;
            default:
                $query .= implode( " , ", $array );
                break;
        }        
        return $query;
    }
}

        //Left
        $user = new User('id'=>1, 'name'=>'User', 'family'=>'Group', 'address'=>'Home');
        
        $db = new \Database\Database();
        $Query = $db -> Build()
               -> addpart( 'INSERT INTO', 'user')
               -> addpart( 'FIELD', $user)
               -> addpart( 'VALUES', ['?','?','?','?'] );
        $db -> apply( $Query );      
        $db -> param = array_values( get_object_vars( $user ) );
        $db -> execute();        

        //right
        $Query = $db -> Build()
               -> addpart( 'UPDATE', 'user')
               -> addpart( 'SET', ['id=?', 'name=?', 'family=?', 'address=?'])
               -> addpart( 'WHERE', ['id=1'] );
        $db -> apply( $Query );
        $db -> param = [2, 'User', 'Group', 'Home'];
        $db -> execute();        
        
        //left
        $Query = $db -> Build()
               -> addpart( 'SELECT', $user )
               -> addpart( 'FROM', ['user'] )
               -> addpart( 'WHERE', ['id > 0'] )
               -> addpart( 'LIMIT', [10] );
        $db -> apply( $Query );
        $res = $db -> query();

        //relax
        var_dump($res);

        //left-right-relax... loop.