Upgrade Model CI3 to CI4

Hi all.
I'm trying to upgrade CI3 to CI4 adding namespace and use,
but Visual Studio code get 'Undefined method select'. 

Thanks in advance for help.

PHP Code:

namespace App\Models; // CI4

use CodeIgniter\Model; // CI4

defined('BASEPATH') OR exit('No direct script access allowed');

class myClass extends Model {

    public function myFunc()
    {

        $this->db->select('id, name'); // <-- UNDEFINED METHOD SELECT
        $this->db->from('table');
        $this->db->where('status', 1);
        $this->db->where('op', '');
        $this->db->group_start();
            $this->db->where('data_cal', NULL);
            $this->db->or_where('data_cal <= NOW()');
        $this->db->group_end();
        $this->db->order_by("id", "DESC");

        $query =  $this->db->get()->result();
        
        if($query) {

            return $query[0];

        } else {
            null;
        }
    }

} 


The $db property contains the connection to the database.
To work with Query Builder you need to get an instance of it.

PHP Code:

$builder = $this->db->table('table');
//or
$builder = $this->builder('table');
//or
property $table = 'table';

$builder = $this->builder();

$builder->select(...)->where(...) 


The result() method no longer exists. Use getResult().
Also orWhere, orderBy, groupStart, etc

https://codeigniter.com/user_guide/database/index.html

Just a Model sample

PHP Code:

<?php

namespace App\Models;

use CodeIgniter\Model;

class SampleModel extends Model
{
    protected $table  = 'yourtable';
    protected $primaryKey = 'id';
        
    protected $allowedFields = ['status', 'name']; // just an example

    public function sample()
    {
        $db = $this->db;
        $query = $db->table('yourtable')
        ->select('id, name')
        ->where('status', 1)
        ...
      ->get();
      
      return $query->getResult(); 
      
    }
} 


Try this I hope it will help you get what you are looking for

PHP Code:

namespace App\Models;

use CodeIgniter\Model;

class myClass extends Model {

    public function myFunc()
    {
        $this->table('table');
        $this->select('id', 'name');
        $this->where(['status' => 1, 'op' => '']); // ->where('status', 1)->where('op', '');
        -----
        -----
        -----

        $query =  $this->getResult();
    }

} 


I just hope it will help you else call me back to it. I am here to help and also receive help