Using UUID as default value in a laravel migration

Question

I have the following migration:

<?php

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

class UpdateRatingGameUserAnswersTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::table('rating_games_user_answers', function (Blueprint $table) {
            $table->uuid('answer_token')->default(DB::raw('UUID()'));
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::table('rating_games_user_answers', function (Blueprint $table) {
            $table->dropColumn('answer_token');
        });
    }
}

As you can see I'm trying to set UUID as default value. I've seen it here

But when I run php artisan migrate I see the following:

What is wrong?

Answer 1

As I came across this question when having the same issue: With MySQL 8 you can use functions as default values. But you need to put paranthesis around them. So this works:

$table->uuid('uid')->default(DB::raw('(UUID())'));

But this won't be compatible with MySQL 5.7!

Answer 2

You cannot use mySQL function as default value it should be either set or you use a trigger.

try please like this:

<?php

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

class UpdateRatingGameUserAnswersTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::table('rating_games_user_answers', function (Blueprint $table) {
            $uuid = DB::raw('select UUID()');
            $table->uuid('answer_token')->default($uuid);
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::table('rating_games_user_answers', function (Blueprint $table) {
            $table->dropColumn('answer_token');
        });
    }
}