PDO Custom Class

config_pdo.php

<?php  
 
function connect_mysql() {
    $mysql_hostname = "localhost";
    $mysql_user = "x";
    $mysql_password = "x";
    $mysql_database = "x"; 
     
    $dbh = new PDO("mysql:host=$mysql_hostname;dbname=$mysql_database", $mysql_user, $mysql_password, 
  array(
    PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
    PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8"
  ));
 
  return $dbh;
}
 
function connect_sqlite() {
    //if doesnt exist, will created.
    $dbh = new PDO('sqlite:dbase.db');
     
    return $dbh;
}
 
function getScalar($db, $sql, $params) {
    if ($stmt = $db -> prepare($sql)) {
 
        $stmt->execute($params);
 
        return $stmt->fetchColumn();
    } else
        return 0;
}
 
function getRow($db, $sql, $params) {
    if ($stmt = $db -> prepare($sql)) {
 
        $stmt->execute($params);
 
        return $stmt->fetch();
    } else
        return 0;
}
 
function getSet($db, $sql, $params) {
    if ($stmt = $db -> prepare($sql)) {
 
        $stmt->execute($params);
 
        return $stmt->fetchAll();
    } else
        return 0;
}
 
function executeSQL($db, $sql, $params) {
    if ($stmt = $db -> prepare($sql)) {
 
        $stmt->execute($params);
 
        return $stmt->rowCount();
    } else
        return false;
}
?>

sample.php

//sample.php
<?php
 
require_once("config_pdo.php");
 
$db = connect_mysql();
 
$user_id = 3;
$a = 1;
$names ="";
 
//example 1
$rows = getSet($db, "select * from users where user_id>? and user_is_active=?", array($user_id,$a)); //always pass as array, when not have parameters pass plain null
 
foreach($rows as $row) {
    $names .= $row['user_name'] . ", ";
}
 
//example 2
$field = = getScalar($db, "select user_working_hour_id from user_working_hours where date_end is null and user_id=? order by user_working_hour_id DESC limit 1",array($user_id));
 
if(!$field ) //when the variable is not filled
    echo "error";
else
    echo $field;
 
//example 3
$row = getRow($db, "select * from user_working_hours where date_end is null and user_id=? order by user_working_hour_id DESC limit 1",array($user_id));
     
if(!$row)  //when the variable is not filled
    echo "error";
else
    echo $r["user_working_hours_start"];