diff --git a/app/Models/Cart.php b/app/Models/Cart.php
index ca3458d..283b9b0 100644
--- a/app/Models/Cart.php
+++ b/app/Models/Cart.php
@@ -12,7 +12,7 @@ class Cart extends Model
     use HasFactory;
 
     protected $fillable = [
-        'status',
+        'status', // CART | DONE
     ];
 
     public function city(): BelongsTo
@@ -29,5 +29,25 @@ class Cart extends Model
     {
         return $this->belongsToMany(Item::class, 'carts_items', 'cart_id', 'item_id');
     }
+
+    public function isEmpty() {
+        return $this->items()->isEmpty();
+    }
+
+    public function setCity($city) {
+        if($this->city == $city)
+            return;
+
+        $this->city = $city;
+
+        if(!$this->isEmpty())
+            $this->dropItems();
+
+        $this->save();
+    }
+
+    public function dropItems() {
+        $this->items()->detach();
+    }
 }
 
diff --git a/app/Models/User.php b/app/Models/User.php
index ceeaade..a3e099b 100644
--- a/app/Models/User.php
+++ b/app/Models/User.php
@@ -18,7 +18,7 @@ class User extends Authenticatable
      * @var array<int, string>
      */
     protected $fillable = [
-        'name',
+        'username',
         'matrix_username',
         'phone',
     ];
diff --git a/database/migrations/2014_10_12_000000_create_users_table.php b/database/migrations/2014_10_12_000000_create_users_table.php
index 9f7aeb5..2d91c19 100644
--- a/database/migrations/2014_10_12_000000_create_users_table.php
+++ b/database/migrations/2014_10_12_000000_create_users_table.php
@@ -13,7 +13,7 @@ return new class extends Migration
     {
         Schema::create('users', function (Blueprint $table) {
             $table->id();
-            $table->string('name');
+            $table->string('username')->unique();
             $table->string('matrix_username')->unique();
             $table->string('phone')->unique();
             $table->timestamps();
diff --git a/database/migrations/2023_06_15_134235_create_carts_table.php b/database/migrations/2023_06_15_134235_create_carts_table.php
index 197c88c..dbd4290 100644
--- a/database/migrations/2023_06_15_134235_create_carts_table.php
+++ b/database/migrations/2023_06_15_134235_create_carts_table.php
@@ -14,7 +14,7 @@ return new class extends Migration
         Schema::create('carts', function (Blueprint $table) {
             $table->id();
             $table->unsignedBiginteger('city_id')->unsigned();
-            $table->unsignedBiginteger('company_id')->unsigned();
+            $table->unsignedBiginteger('company_id')->unsigned()->nullable();
             $table->unsignedBiginteger('user_id')->unsigned();
             $table->string('status'); // CART | DONE