PHP OOP PDO

dao.php

<?php
 
// Database Access Object
class dao {
    private $db = NULL;
    private $connection_string = NULL;
    private $db_type = DB_TYPE;
    private $db_path = DB_PATH;
    private $db_host = DB_HOST;        
    private $db_user = DB_USER;        
    private $db_pass = DB_PASS;        
    private $db_name = DB_NAME;        
    private $con = false;
 
    public function __construct($db_user = DB_USER, $db_pass = DB_PASS, $db_name = DB_NAME, $db_type = 'mysql', $db_path = DB_PATH, $db_host = 'localhost')
    {
        $this->db_host = $db_host;
        $this->db_user = $db_user;
        $this->db_pass = $db_pass;
        $this->db_name = $db_name;
        $this->db_path = $db_path;
        $this->db_type = $db_type;
 
        switch($this->db_type){
            case "mysql":
            $this->connection_string = "mysql:host=".$db_host.";dbname=".$db_name;
            break;
             
            case "sqlite":
            $this->connection_string = "sqlite:".$db_path;
            break;
             
            case "oracle":
            $this->connection_string = "OCI:dbname=".$db_name.";charset=UTF-8";
            break;
             
            case "dblib":
            $this->connection_string = "dblib:host=".$db_host.";dbname=".$db_name;
            break;
             
            case "postgresql":
            $this->connection_string = "pgsql:host=".$db_host." dbname=".$db_name;
            break;
            
            case "sqlsrv":
            $this->connection_string = "sqlsrv:Server=".$db_host.";Database=".$db_name;
            break;
        }
        return $this;
    }
 
    public function connect() {
        if(!$this->con) {
            try {
                $this->db = new PDO($this->connection_string,$this->db_user, $this->db_pass);
                $this->db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
                $this->con = true;
                return $this->con;
            } catch (PDOException $e) {
                return $e->getMessage();
            }
        } else {
            return true;
        }
    }
 
    public function disconnect() {
        if($this->con) {
            unset($this->db);$this->con = false;
            return true;
        }
    }
    
    /**
    $db = new dao('username','password','database');
    $db->connect();
    if ($db->connect()) {
      echo "tersambung dengan database";
    } else {
      echo "gagal tersambung"
    $db->disconnect(); // kalau mau disconnect
    **/
    
    // SELECT
    public function select($table, $rows = '*', $where = null, $order = null) {
        if($this->tableExists($table)) {
            $q = 'SELECT '.$rows.' FROM '.$table;
            if($where != null)
                $q .= ' WHERE '.$where;
            if($order != null)
                $q .= ' ORDER BY '.$order;
            $this->numResults = null;
            try {
                $sql = $this->db->prepare($q);
                $sql->execute();
                $this->result = $sql->fetchAll(PDO::FETCH_ASSOC);
                $this->numResults = count($this->result);
                $this->numResults === 0 ? $this->result = null : true ;
                return true;
            } catch (PDOException $e) {
                return $e->getMessage().''.$e->getTraceAsString().''; 
            } 
        } 
    }
    
    public function getResult(){
        return $this->result;
    }
    
    /**
    $result = $db->select('users');
    if ($result === true){
        echo "result select ";
        print_r($db->getResult());
    } else {
        var_dump($result);
    }
    **/
    
    // INSERT
    public function insert ($table,$values,$rows = null) {
        $insert = 'INSERT INTO '.$table;
        if($rows != null) {
            $insert .= ' ('.$rows.')';
        }
     
        for($i = 0; $i < count($values); $i++) {
            if(is_string($values[$i]))
                $values[$i] = '"'.$values[$i].'"';
        }
     
        $values = implode(',',$values);
        $insert .= ' VALUES ('.$values.')';
     
        try {
            $ins = $this->db->prepare($insert);
            $ins->execute();
            return true;
        } catch (PDOException $e) {
            return $e->getMessage();
        }
    }
    
    /**
    $result = $db->insert("user", array("","test123","test","0"), "id,username,password,active");
    **/
    
}