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?

As I remember. UUID() is default function in mysql. See here https://mysqlserverteam.com/storing-uuid-values-in-mysql-tables/ For example, the request `SELECT UUID()` gives me uuid. — Aleksej_Shherbak, Feb 25 '19 at 12:51

score 28 · Accepted Answer · answered Dec 11 '20 at 22:45

28

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!

answered Dec 11 '20 at 22:45

Sindhara

1,423
13
20

The postgres compatible version is `$table->uuid('uid')->default(DB::raw('(gen_random_uuid())'));`. – James Hulse Aug 31 '23 at 01:33

score 3 · Answer 2 · answered Feb 25 '19 at 13:10

3

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');
        });
    }
}

answered Feb 25 '19 at 13:10

Alpy

759
6
9

1

Why? I can use `NOW()` for example. And it's work. I have updated my code to `$table->dateTime('answer_token')->default(DB::raw('NOW()'));` and it works nice. I can see default dateTime values in my database. – Aleksej_Shherbak Feb 25 '19 at 13:17
NOW() it may be an exception but see here https://forums.mysql.com/read.php?10,91149,91161#msg-91161 – Alpy Feb 25 '19 at 13:25
Sorry but I don't understand. I have not written a trigger for the `NOW()` and it works. Which difference between `NOW()` and `UUID()`. Both are functions, right? From your link I'he understood that I need to make a trigger for a calling `UUID()`. So why I don't have to do it for `NOW()`? – Aleksej_Shherbak Feb 25 '19 at 13:36
Normally it should not work `With one exception, the default value specified in a DEFAULT clause must be a literal constant; it cannot be a function or an expression. This means, for example, that you cannot set the default for a date column to be the value of a function such as NOW() or CURRENT_DATE. ` https://dev.mysql.com/doc/refman/5.7/en/data-type-defaults.html as for your issue the trigger or pre-query should solve it. – Alpy Feb 25 '19 at 13:48

Using UUID as default value in a laravel migration

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