adding a cart

app/Models/Cart.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace App\Models;
+
+use Database\Factories\CartFactory;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
+
+class Cart extends Model
+{
+    /** @use HasFactory<CartFactory> */
+    use HasFactory;
+
+    protected $fillable = ['user_id'];
+
+    public function user(): BelongsTo
+    {
+        return $this->belongsTo(User::class);
+    }
+
+    public function products(): BelongsToMany
+    {
+        return $this->belongsToMany(Product::class)->withPivot('quantity');
+    }
+}

app/Models/User.php

@@ -7,6 +7,7 @@ use Database\Factories\UserFactory;
 use Illuminate\Database\Eloquent\Attributes\Fillable;
 use Illuminate\Database\Eloquent\Attributes\Hidden;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Relations\HasOne;
 use Illuminate\Foundation\Auth\User as Authenticatable;
 use Illuminate\Notifications\Notifiable;
 use Laravel\Fortify\TwoFactorAuthenticatable;
@@ -18,6 +19,11 @@ class User extends Authenticatable
     /** @use HasFactory<UserFactory> */
     use HasFactory, Notifiable, TwoFactorAuthenticatable;
 
+    public function cart(): HasOne
+    {
+        return $this->hasOne(Cart::class);
+    }
+
     /**
      * Get the attributes that should be cast.
      *