README

# CodeIgniter-3.X-Extension-
Related extensions to CodeIgniter 3.x Framework are available here

Student.php

<?php

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

class Student extends \MY_Model{
	
	public $tableName = "student";
	public $id,$name,$age;
	
	public function getCard(){
		return $this->hasOne(\Card::class,"id","studentId");
	}
	
	public function getBooks(){
		return $this->hasMany(\Book::class,"id","studentId");
	}
	
	public function getTeachers(){
		return $this->belongsToMany("studentteacher", \Teacher::class, "id", "studentId", "id", "teacherId");
	}
}

Book.php

<?php

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

class Book extends \MY_Model {
	public $tableName = "book";
	public $id,$studentId,$name,$price;
	
	public function getStudent(){
		return $this->belongsTo(\Student::class,"id","studentId");
	}
}



In your controller:

public function index()
{		
	$this->load->model("Student");
	$student = $this->Student;

	var_dump($student->getCount());
}