<?php
class Database
{
    private $host;
    private $port;
    private $dbname;
    private $user;
    private $password;
    protected $conn;

    public function __construct($host, $port, $dbname, $user, $password) {
        $this->host = $host;
        $this->port = $port;
        $this->dbname = $dbname;
        $this->user = $user;
        $this->password = $password;
    }

    function error($error, $id)
    {
        // throw new Exception($error, $id);
        echo $error.", ". $id;
        die;

    }

    public function connect()
    {
        $result = $this->conn = pg_connect("host=$this->host port=$this->port dbname=$this->dbname user=$this->user password=$this->password");

        if (!$result) {
            return $this->error("Blad polaczenia", 1);
        } else {
            echo '<span style="float:right;color:red;background-color:black;">Połączono z bazą danych.</span><br />';
        }
    }
}
?>

________________________________________________________________________________________________________________________________

<?php

require "db.php";

class Result extends Database
{
    private $save;
    public function __construct() {
        parent::__construct("127.0.0.1", 5432, "blue", "postgres", "postgres");
    }

    public function validate($value = null, $secondData = null)
    {

        $sql = 'INSERT INTO test(surname) VALUES(:symbol)';
        $stmt = $this->conn->prepare($sql);
        $stmt->bindValue(':symbol', "cos_tam");
        $stmt->execute();
        return "save";

    }
}