Model

<?php
error_reporting(0);
/***
table:
CREATE TABLE `pendaftar` (
  `id` int(11) NOT NULL,
  `nik` char(16) NOT NULL,
  `nama` varchar(150) NOT NULL,
  `alamat` text NOT NULL,
  `surel` varchar(250) NOT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4;
ALTER TABLE `pendaftar`
  ADD PRIMARY KEY (`id`),
  ADD UNIQUE KEY `nik` (`nik`),
  ADD UNIQUE KEY `sureal` (`surel`),
  ADD KEY `nama` (`nama`);
ALTER TABLE `pendaftar`
  MODIFY `id` int(11) NOT NULL AUTO_INCREMENT;
***/
class Db
{
    private $dbsetup;
    public $conn;
    private $sql;
    public function __construct($dbsetup)
    {
        $this->dbsetup= $dbsetup;
        $this->conn=false;
    }

    public function db()
    {
        $dbsetup = $this->dbsetup;
        if($this->conn) return $this;

        try {
            // $db = new PDO("mysql:host=localhost;dbname=senggol", "root", "");
            //die(print_r($dbsetup));
            $this->conn = new PDO("mysql:host=" . $dbsetup['host'] . ";dbname=" . $dbsetup['name'] . "", $dbsetup['user'], $dbsetup['pass']);
            $this->conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
            //echo "Connection successful" . PHP_EOL . "";
            // echo "Data Pendaftaran Pasar Senggol: " . PHP_EOL . "";
            // $sql = "SELECT * FROM pendaftar";
            // $pendaftar = $this->conn->query($sql);
            // foreach ($pendaftar as $daftar) {
            //     echo "Id: " . $daftar["idpendaftar"] . "" . PHP_EOL . "";
            //     echo "Tahun: " . $daftar["tahun"] . "" . PHP_EOL . "";
            //     echo "Bulan: " . $daftar["bulan"] . "" . PHP_EOL . "";
            //     echo "NIK: " . $daftar["nik"] . "" . PHP_EOL . "";
            //     echo "Nama: " . $daftar["nama"] . "" . PHP_EOL . "";
            //     echo "Alamat: " . $daftar["alamat"] . "" . PHP_EOL . "";
            //     echo "Surel: " . $daftar["surel"] . "";
            // }
            return $this;
        } catch (PDOException $e) {
            die("Connection failed : " . $e->getMessage());
        }
    }

    public function beginTransaction()
    {
        $this->conn->beginTransaction();
        return $this;
    }

    public function commit()
    {
        $this->conn->commit();
        return $this;
    }

    public function countRegisteration($data)
    {
        $nik = $data['nik'];
        $sql = $this->conn->prepare("SELECT COUNT(*) FROM pendaftar WHERE nik=?");
        $sql->bindValue(1, $nik);

        $this->sql = $sql;
        return $this;
    }

    public function st()
    {
        $this->sql->execute();
        return $this;
    }

    public function fetchColumn()
    {
        return $this->sql->fetchColumn();
    }

    public function addRegistration($data)
    {
        $sql = "INSERT INTO pendaftar (nik, nama, alamat, surel) VALUES (?, ?, ?, ?)";
        $sql = $this->conn->prepare($sql);
        $sql->bindValue(1, @$data['nik']);
        $sql->bindValue(2, @$data['nama']);
        $sql->bindValue(3, @$data['alamat']);
        $sql->bindValue(4, @$data['surel']);
        $sql->execute( );

        return true;
    }

    // public function lastInsertId()
    // {
        // return $this->sql->lastInsertId();
    // }

    public function rollBack()
    {
        return $this->sql->rollBack();
    }
    public function lastInsertId()
    {
        return $this->conn->lastInsertId();
    }


    public function countRegistration($data)
    {
        $sql="select count(*) c from pendaftar where nik=?";
        //var_dump($this->conn);
        $this->sql = $this->conn->prepare($sql);
        $this->sql->bindValue(1, $data['nik']??0);
        return $this;
    }
}