can not run migration

[hashan]

public function up()
{
    Schema::create('registerusers', function (Blueprint $table) {
        $table->increments('id');
        $table->string('firstname', 10);
        $table->string('lastname', 20);
        $table->integer('phone', 10);
        $table->string('email')->unique();
        $table->string('gender');
        $table->string('vehiclemodel');
        $table->string('platenum', 6);
        $table->timestamps();
    });
}

Erroris : Illuminate\Database\QueryException : SQLSTATE[42000]: Syntax error or access violation: 1075 Incorrect table definition; there can be only one auto column and it must be defined as a key

[Nubelle]

othana tiyena integer eka unsigned karana

$table->integer('phone',10)->unsigned();

[hashan]

SQLSTATE[HY000]: General error: 1364 Field 'username' doesn't have a default value (SQL: insert into registerusers (updated_at, created_at) values (2019-07-15 12:03:06, 2019-07-15 12:03:06))
menna me error eka enwa, data base ekata data sav krnna giama.

public function storeRegister(Request $request)
{
$registeruser = new registeruser;
$request->all();
$registeruser->save();
}

[dev_lak]

username kyna field ekata value ekak naha kyla kyanne

[Nubelle]

@hashan row sql use krane ai mchan , Laravel ORM eka use karana