How can I update an existing Eloquent relationship in Laravel 4?

Taylor Otwell's official answer is the following:

$account = Account::find(99);
User::find(1)->account()->associate($account)->save();

I couldn't find the associate() method in the official docs. So if someone else is looking for a solution to this. Here you go!

This is how i would have done it

 //step 1

My migrations

class CreateUsersTable extends Migration {

     public function up()
     {
         Schema::create('users', function(Blueprint $table) {
             $table->engine = 'InnoDB';
             $table->increments('id');
             $table->string('first_name');
             $table->string('last_name');
             $table->timestamps();
         });
     }

     public function down()
     {
         Schema::drop('users');
     }

 }

 class CreateUserDetailsTable extends Migration {

     public function up()
     {
         Schema::create('user_details', function(Blueprint $table) {
             $table->engine = 'InnoDB';
             $table->increments('id');
             $table->integer('user_id')->unsigned()->unique('user_id', 'user_details_user_id');
             $table->foreign('user_id')->references('id')->on('users');
             $table->enum('gender', array('male', 'female'))->nullable();
             $table->string('city')->nullable();
             $table->date('date_of_birth')->nullable();
             $table->timestamps();
         });
     }

     public function down()
     {
         Schema::drop('user_details');
     }

 }

Then

 //step 2

My base models

 class UserDetail extends Eloquent {

     protected $guarded = array();

     protected $table = 'user_details';

     public function user()
     {
        return $this->belongsTo('User');
     }
 }

 class User extends Eloquent {

     protected $table = 'users';

     protected $guarded = array();

     public function detail()
     {
         return $this->hasOne('UserDetail');
     }
 }

Then

 //step 3

My Controllers - Updating user_details schema

  //When Updating records i get the raw data from say an input
  $detail = Input::all();

  //then find the user
  $user = User::find(1);

  //then update the details
  $detail = $user->detail()->update($detail);

  //then respond back with the detail
  Response::json($detail);

My Controllers - creating user_details schema

  //again get data input from source, the source does not come with user id
  $detail = Input::all();

  //when creating new record
  $detail = new UserDetail($detail);
  $detail = $user->detail()->save($detail);
  return Response::json($detail);

And thats it for creating and updating new records using Laravel 4's belongsTo relationships

Hey you can refer the laravel docs for the solution.

Link http://laravel.com/docs/4.2/eloquent#inserting-related-models

$account = Account::find(10);

$user->account()->associate($account);

$user->save();