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I'm trying to define a role for my users using a "role_id" foreign key which referes to the "id" of my "roles" table.

The migrations worked well but when I'm trying to register I get an error.

Migration users

class CreateUsersTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('users', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->char('nni', 6);
            $table->string('firstname');
            $table->string('lastname');
            $table->string('email')->unique();
            $table->unsignedBigInteger('role_id')->default(1);
            $table->timestamp('email_verified_at')->nullable();
            $table->string('password');
            $table->rememberToken();
            $table->timestamps();

            $table->foreign('role_id')->references('id')->on('roles');
        });
    }

Models/User

class User extends Authenticatable
{
    use Notifiable;

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'nni', 'firstname', 'lastname', 'email', 'role_id', 'admin', 'password',
    ];

[...]

public function role()
    {
        return $this->belongsTo(Role::class);
    }
}

Migration roles

class CreateRolesTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('roles', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->string('name');
            $table->string('description');
            $table->timestamps();
        });
    }

[...]

}

The error

SQLSTATE[23000]: Integrity constraint violation: 1452 Cannot add or update >a child row: a foreign key constraint fails (projectsms.users, >CONSTRAINT users_role_id_foreign FOREIGN KEY (role_id) REFERENCES >roles (id))

If you know where is my problem let me know !

Petoux
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  • note the migration order. if the `users` table is being created before the `roles` table, it will fail the constraint when it tries to create. foreign tables should be created first before trying to reference them. – Erich Aug 23 '19 at 12:57
  • The value of the `role_id` doesnt reference an entry in your `roles` table. Is there a role id = 1 in your `roles` table ? `$table->unsignedBigInteger('role_id')->default(1);` – N69S Aug 23 '19 at 13:02
  • Tried, and got this : `SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint (SQL: alter table `users` add constraint `users_role_id_foreign` foreign key (`role_id`) references `roles` (`id`))` – Petoux Aug 23 '19 at 13:02
  • @N69S I have no role_id = 1 in my roles table, why would I have it? – Petoux Aug 23 '19 at 13:03
  • @Petoux because you set the default value of `role_id` in the table `users` to 1. If you have users without roles, set the field as nullable `$table->unsignedBigInteger('role_id')->nullable();` – N69S Aug 23 '19 at 13:05
  • @N69S I want the default role to be 1, and all users with a role, how can I do that ? EDIT : Worked, I found my error, thank you ! – Petoux Aug 23 '19 at 13:08

2 Answers2

1

Since your structure depends on the fact that every use must have a role, you should include the insertion of the default role in your migration.

class CreateRolesTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('roles', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->string('name');
            $table->string('description');
            $table->timestamps();
        });

        DB::table('roles')->insert([
            'id' => 1, //must be 1
            'name' => 'default',
            'description' => 'default role (just registered)',
            'created_at' => \Carbon\Carbon::now(),
            'updated_at' => \Carbon\Carbon::now(),
        ]);
    }

[...]

}
N69S
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0

This happens because, by default, every foreign key HAS to point to an existent primary key. You have three alternatives.

  • 1 Set the default value for role_id an existing id.

  • 2 Delete all registers from roles table before migrate.

  • 3 Set role_id as nullable()

Styl Bandeira
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