safekat/ci4/app/Models/ChatUser.php

<?php

namespace App\Models;

use CodeIgniter\Model;

class ChatUser extends Model
{
    protected $table            = 'chat_users';
    protected $primaryKey       = 'id';
    protected $useAutoIncrement = true;
    protected $returnType       = 'array';
    protected $useSoftDeletes   = true;
    protected $protectFields    = true;
    protected $allowedFields    = [
        "user_id",
        "chat_id"
    ];

    protected bool $allowEmptyInserts = false;
    protected bool $updateOnlyChanged = true;

    protected array $casts = [];
    protected array $castHandlers = [];

    // Dates
    protected $useTimestamps = true;
    protected $dateFormat    = 'datetime';
    protected $createdField  = 'created_at';
    protected $updatedField  = 'updated_at';
    protected $deletedField  = 'deleted_at';

    // Validation
    protected $validationRules      = [];
    protected $validationMessages   = [];
    protected $skipValidation       = false;
    protected $cleanValidationRules = true;

    // Callbacks
    protected $allowCallbacks = true;
    protected $beforeInsert   = [];
    protected $afterInsert    = [];
    protected $beforeUpdate   = [];
    protected $afterUpdate    = [];
    protected $beforeFind     = [];
    protected $afterFind      = [];
    protected $beforeDelete   = [];
    protected $afterDelete    = [];
    public function getChatUserArrayId(int $chat_id) : array
    {
        $queryResult = $this->builder()
        ->select(['chat_users.user_id'])
        ->where("chat_users.chat_id",$chat_id)
        ->get()->getResultObject();
        return array_map(fn($q) => $q->user_id,$queryResult);
    }
}