如何连接 laravel 中的表

Question

I have three tables that want to join them together. first table is questions, second is sections and third is options. I want to fetch all records of table questions where formid for example is 120 and all records of table sections where it's questionid is equal to questionid of fetched questions table questionid. And all record of third table 'options' where options.questionid=questions.questionid.

    $questions=DB::table('sections')
            ->rightJoin('questions',function($join ){
                $join->on('questions.questionid','=','sections.questionid');
            })
            ->leftJoin('options',function($join ){
                $join->on('questions.questionid','=','options.questionid');
            })
            ->where('questions.formid',$formId)
            ->get();

This code return null for questionid where no matched in sections table. How to solve this issue?

Answer 1

Try it.

$questions=DB::table('questions')
        ->join('sections',function($join ){
            $join->on('questions.questionid','=','sections.questionid');
        })
        ->join('options',function($join ){
            $join->on('questions.questionid','=','options.questionid');
        })
        ->where('questions.formid',$formId)
        ->get();