PianoTime/database/migrations/2018_06_28_092245_create_remarks_table.php

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateRemarksTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('remarks', function (Blueprint $table) {
            $table->increments('id');
            $table->unsignedInteger('teacher_id')->nullable()->comment('讲师ID');
            $table->unsignedInteger('course_id')->nullable()->comment('课程ID');
            $table->unsignedInteger('student_id')->nullable()->comment('学员ID');
            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('remarks');
    }
}