add assessment feature

app/Models/StudentAnswerModel.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace App\Models;
+
+use CodeIgniter\Model;
+
+class StudentAnswerModel extends Model
+{
+    protected $table = 'student_answers';
+    protected $primaryKey = 'id';
+    protected $returnType = 'array';
+    protected $allowedFields = ['student_assessment_id', 'question_id', 'answer_value', 'is_correct', 'points_awarded'];
+    protected $useTimestamps = true;
+}