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'); } }