<?php

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

class CreateRevisionRowPivotTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('revision_row_pivot', function (Blueprint $table) {
            $table->unsignedInteger('revision_id')->index();
            $table->unsignedInteger('row_id')->index();

            $table->foreign('revision_id')->references('id')->on('revisions')
                ->onDelete('cascade');

            // ensure backward integrity constraint (but normally a row should not be deleted unless it's ref is 0)
            $table->foreign('row_id')->references('id')->on('rows');
        });
    }

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