PDO class for MySQL

config.php

<?php

// Define configuration  
define("DB_HOST", "localhost");  
define("DB_USER", "user");  
define("DB_PASS", "password");  
define("DB_NAME", "schema_name");  

database.php

<?php  
// As explained in https://www.culttt.com/2012/10/01/roll-your-own-pdo-php-class/ where there are also some usage examples.
namespace example;

use PDO;

include('config.php'); // where constants were defined

class Database{
    private $host = DB_HOST;  
    private $user = DB_USER;  
    private $pass = DB_PASS;  
    private $dbname = DB_NAME;  
    private $dbh;  
    private $error;  
    private $stmt;  
 

    
    public function __construct(){
        // set DSN
        $dsn = 'mysql:host=' . $this->host . ';dbname=' . $this->dbname; 
        // Set options  
        $options = array(  
        PDO::ATTR_PERSISTENT => true,  
        PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION  
        );  
        try {  
        $this->dbh = new \PDO($dsn, $this->user, $this->pass, $options);  
        } 
        // Catch any errors  
        catch (PDOException $e) {  
        $this->error = $e->getMessage();  
        }  
        
    }  
    
    public function query($query){  
    $this->stmt = $this->dbh->prepare($query);  
    }  
    
    public function bind($param, $value, $type = null){  
    if (is_null($type)) {  
    switch (true) {  
    case is_int($value):  
    $type = PDO::PARAM_INT;  
    break;  
    case is_bool($value):  
    $type = PDO::PARAM_BOOL;  
    break;  
    case is_null($value):  
    $type = PDO::PARAM_NULL;  
    break;  
    default:  
    $type = PDO::PARAM_STR;  
    }  
    }  
    $this->stmt->bindValue($param, $value, $type);  
    }  
    
    public function execute(){  
    return $this->stmt->execute();  
    }  
    
    public function resultset(){  
    $this->execute();  
    return $this->stmt->fetchAll(PDO::FETCH_ASSOC);  
    }  
    
    public function single(){  
    $this->execute();  
    return $this->stmt->fetch(PDO::FETCH_ASSOC);  
    }
    
    public function rowCount(){  
    return $this->stmt->rowCount();  
    }  
    
    public function lastInsertId(){  
    return $this->dbh->lastInsertId();  
    }  
    
    public function beginTransaction(){  
    return $this->dbh->beginTransaction();  
    }  
    
    public function endTransaction(){  
    return $this->dbh->commit();  
    }
    
    public function cancelTransaction(){  
    return $this->dbh->rollBack();  
    }
    
    public function debugDumpParams(){  
    return $this->stmt->debugDumpParams();  
    }  

}