<?php namespace App\Models\System;

use CodeIgniter\Model;

class User_model extends Model

{

    var $Db;

    function __construct()

    {

        parent::__construct();

        //创建数据库连接

        $this->Db = \Config\Database::connect();

    }

    function updatadata()

    {

        $data = array(

            'MARK' => '马克1',

            'USER_NAME' => '张三2',

        );

        $builder = $this->Db->table('tp_user')->where('ID', 160);

        $builder->update($data);

    }
}

<?php namespace App\Controllers;

class Home extends BaseController

{

    //http://127.0.0.1/CI4/public/

    //http://127.0.0.1/CI4/public/index.php/home

    //http://127.0.0.1/CI4/public/index.php/home/insertdata

    var $User_Models;

    function __construct()

    {

        //创建数据库连接

        $this->User_Models = new \App\Models\System\User_model();

    }

    public function index()

    {

        //调用我们的Lib库文件

        $Mylib = new \App\Libraries\mylib();

        //赋值

        $Mylib->setAge(18);

        $Mylib->setName('张三');

        //输出

        echo $Mylib->getAge() . '<br>';

        echo $Mylib->getName() . '<br>';

        echo '青青子衿悠悠我心';

    }

    public function updata()

    {

        $rst = $this->User_Models->updatadata();

    }

}