在Laravel 5中使用UUID作为主键

Question

I'm trying to create tables that will have a primary key which is a UUID defined as binary(16) instead of the default auto-incrementing id field.

I've managed to create migrations using raw SQL statements though DB::statement like so:

DB::statement("CREATE TABLE `binary_primary_keys` (
                      `uuid` binary(16) NOT NULL DEFAULT '\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0',
                      `created_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
                      `updated_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
                      PRIMARY KEY (`uuid`)
                  ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;");

However, I have trouble getting the model working. I've followed the tutorial available here . I've defined my model like so:

class UuidModel extends Model
{
    public $incrementing = false;
    public $primaryKey = 'uuid';

    /**
     * The "booting" method of the model.
     *
     * @return void
     */
    protected static function boot()
    {
        parent::boot();

        /**
         * Attach to the 'creating' Model Event to provide a UUID
         * for the `id` field (provided by $model->getKeyName())
         */
        static::creating(function ($model) {
            $model->{$model->getKeyName()} = (string)$model->generateNewId();
            echo($model->{$model->getKeyName()});
        });
    }

    /**
     * Get a new version 4 (random) UUID.
     */
    public function generateNewId()
    {
        return Uuid::generate();
    }
}

where Uuid is an alias to Webpatser\\Uuid .

One problem, I'm having is I cannot derive UuidModel from Eloquent as explained in the tutorial. In fact I don't see an Eloquent class. I'm deriving from Model instead. I am guessing the tutorial was written in Laravel 4.

I would appreciate help in implementing tables with UUIDs as primary keys in Laravel 5.

EDIT 1: So, if I define my class like so:

use Illuminate\Database\Eloquent
class UuidModel extends Eloquent { ... }

I get the following error:

PHP Fatal error:  Class 'Illuminate\Database\Eloquent' not found in /home/vagrant/transactly/app/UuidModel.php on line 8

If I remove the use Illuminate\\Database\\Eloquent line, I get the following error:

PHP Fatal error:  Class 'App\Eloquent' not found in /home/vagrant/transactly/app/UuidModel.php on line 8

Edit 2: I have discovered that the static::creating event is never called for when instances of UuidModel are created.

I tried setting up the creating event listener in AppServiceProvider but that's not being called as well. Interestingly, the creating event is not called for a regular Laravel generated model User either.

class AppServiceProvider extends ServiceProvider
{
/**
 * Bootstrap any application services.
 *
 * @return void
 */
public function boot()
{
    /**
     * Attach to the 'creating' Model Event to provide a UUID
     * for the `id` field (provided by $model->getKeyName())
     */
    echo "Booting...\n";
    UuidModel::creating(function ($model) {
        echo "Creating Uuid Model...\n";
        $model->{$model->getKeyName()} = (string)$model->generateNewId();
    });

    User::creating(function($user){
        echo "Creating User Model...";
        $user->name = 'Forced Name in boot()';
    });
}
public function register(){}

}

Answer 1

So, I got the thing working like a charm (not tested unit testing):

1. class UuidModel extends Eloquent is an older (Laravel 4) construct. We use class UuidModel extends Model in Laravel 5

2. The solution was to move the

    UuidModel::creating(function ($model) { echo "Creating Uuid Model...\\n"; $model->{$model->getKeyName()} = (string)$model->generateNewId(); }); 

   from AppServiceProvider::boot() to EventServiceProvider::boot() . No other changes were required. Everything worked as expected.

I still don't know why (2) works in EventServiceProvider and not in AppServiceProvider as explained in the official docs . But judging from the name, that's perhaps the way it was meant to be.

Answer 2

How about this idea for storing a 36chr UUID as Binary(16) :

IMO there is an advantage in not having Laravel generating the UUID . Namely, if new records (some day in the future) get inserted into the database from outside the application the UUID field is properly populated.

My suggestion: Create a UUID default value trigger using migrations

(this trigger makes the DataBase server do the work to generate the UUID each time a new customer is inserted)

<?php namespace MegaBank\HighInterestLoans\Updates;
    use Illuminate\Database\Schema\Blueprint;
    use Illuminate\Database\Migrations\Migration;

class MigrationTriggerForCustomers extends Migration
{
public function up()
    {

        DB::unprepared('CREATE TRIGGER before_insert_customers
                      BEFORE INSERT ON    
                    `megabank_highinterestloans_customers` 
                      FOR EACH ROW
                      SET new.uuid = UNHEX(REPLACE(UUID(), "-","");');
    }

    public function down()
    {
        DB::unprepared('DROP TRIGGER `before_insert_customers`');
    }
}

Finally, if you want to get a human-readable version of your UUID just do the following:

SELECT HEX(UUID) FROM customers;

Anyway, hope this helps someone :-)

Answer 3

This is a quick solution without using events.

UUidModel.php

<?php        namespace App;

    use \Illuminate\Database\Eloquent\Model;

    use \Illuminate\Database\Eloquent\Builder;

    class UuidModel extends Model

    {

    /**

    * Insert the given attributes and set the ID on the model.

    *

    * @param  \Illuminate\Database\Eloquent\Builder  $query

    * @param  array  $attributes

    * @return void

    */

        protected function insertAndSetId(Builder $query, $attributes)

        {
            $keyName = $this->getKeyName();
            $id = $attributes[$keyName] = $this->generateNewId();
            $query->insert($attributes);
            $this->setAttribute($keyName, $id);
        }

    /**
    * Get a new version 4 (random) UUID.
    */
        public function generateNewId()
        {
            return 'uuid!!' ;// just for test
        }
    }
?>

Model Example Car.php

<?php namespace App;

    class Car extends UuidModel {
    }

Answer 4

also try use this package will automatically generate and assign UUID field in your model, also can show and update by UUIDs key.

https://github.com/EmadAdly/laravel-uuid