How to check for a value on a different table? - php

Question

I have 2 tables one called Exams and the other Exam Results. In the exam I enter the passing_score and in the Exam Results I save the answer of the exam. I'm trying to look up the passing_score and if the passing score is greater then the result then the person passed.
Here is the entire function of this code
public function exam($course_id, Request $request)
{
$course = Course::where('id', $course_id)->firstOrFail();
$answers = [];
$exam_score = 0;
foreach ($request->get('question') as $question_id => $answer_id) {
$question = ExamQuestion::find($question_id);
$correct_answer = ExamOption::where('exam_question_id', $question_id)
->where('id', $answer_id)
->where('is_correct', 1)->count() > 0;
$answers[] = [
'exam_question_id' => $question_id,
'exam_option_id' => $answer_id,
'corect' => $correct_answer
];
if ($correct_answer) {
$exam_score += $question->score;
}
}
$exam_result = ExamResult::create([
'exam_id' => $course->exam->id,
'employee_id' => \Auth::id(),
'result' => $exam_score,
]);
$exam_result->answers()->createMany($answers);
$exam_id = ExamResult::all();
$final_results = Exam::where('id', $exam_id)->get(['passing_grade']);
$val = $final_results->passing_grade;
if($exam_result->result >= $val) {
$exam_result->is_complete = 1;
$exam_result->save();
}
return redirect()->route('learn.show', [$course, $request])->with('message', 'Test score: ' . $exam_score);
}
Here is the logic I've tried and I get stuck.
$exam_id = ExamResult::all();
$final_results = Exam::where('id', $exam_id)->get('passing_grade');
$val = $final_results->passing_grade;
if($exam_result->result >= $val) {
$exam_result->is_complete = 1;
$exam_result->save();
}
Here is the error I'm getting
Argument 1 passed to Illuminate\Database\Grammar::columnize() must be
of the type array, string given, called in
/Applications/MAMP/htdocs/QuickHS/vendor/laravel/framework/src/Illuminate/Database/Query/Grammars/Grammar.php
on line 137
Here is the database structure for the 2 tables
This is the exam table
This is the exam results table

Answer 1

Here is the correction. Please try this.
$final_results = Exam::where('id', $exam_id)->first();
$val = $final_results->passing_grade;

Answer 2

I've resolved it and here is how I did it
$final_results= Exam::first();
$x = $final_results->passing_grade;
if($exam_result->result >= $x)
{
$exam_result->is_complete = 1;
$exam_result->save();
}