Add Pivot table for the relationship between Cities and Companies.

app/Models/City.php

@@ -4,6 +4,7 @@ namespace App\Models;
 
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
 
 class City extends Model
 {
@@ -15,6 +16,11 @@ class City extends Model
         'url',
     ];
 
+    public function companies(): BelongsToMany
+    {
+        return $this->belongsToMany(Company::class, 'cities_companies', 'city_id', 'company_id');
+    }
+
     public static function validate_with_name(string $name)
     {
         $name = $name ?? '';

app/Models/Company.php

@@ -5,6 +5,7 @@ namespace App\Models;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\HasMany;
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
 
 class Company extends Model
 {
@@ -17,6 +18,11 @@ class Company extends Model
         'description',
     ];
 
+    public function cities(): BelongsToMany
+    {
+        return $this->belongsToMany(City::class, 'cities_companies', 'company_id', 'city_id');
+    }
+
     public function categories(): HasMany
     {
         return $this->hasMany(Category::class);

database/migrations/2023_06_19_174521_create_cities_companies_table.php

@@ -0,0 +1,35 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::create('cities_companies', function (Blueprint $table) {
+            $table->id();
+            $table->unsignedBiginteger('city_id')->unsigned();
+            $table->unsignedBiginteger('company_id')->unsigned();
+
+            $table->foreign('city_id')->references('id')
+                 ->on('cities')->onDelete('cascade');
+            $table->foreign('company_id')->references('id')
+                ->on('companies')->onDelete('cascade');
+
+            $table->timestamps();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::dropIfExists('cities_companies');
+    }
+};