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Laravel provides powerful support for Many-to-Many Polymorphic Relationships, allowing a single table to be associated with multiple models through a pivot table. What is a Many-to-Many Polymorphic Relationship? A Many-to-Many Polymorphic Relationship allows a parent model to be associated with multiple instances of different child models through a pivot table, and vice versa. In this post, we'll look at an example where you have a "Tag" model that can be applied to both "Post" and "Video" models. Here, "Post" and "Video" are the parent classes, and "Tag" is the child class. The following diagram illustrates how the database will look like: Diagram Showing the Tables Involved in a Many-to-Many Polymorphic Relationship : tags, taggables, posts and videos Let's get started! Step 1: Create and Run the Migrations First, create the migration files for each entity using the Artisan command: php artisan make:migration create_tags_table --create=tags php artisan make:migration create_posts_table --create=posts php artisan make:migration create_videos_table --create=videos php artisan make:migration create_taggables_table --create=taggables Modify the migration files as follows: For the tags table migration: use Illuminate\Database\Migrations\Migration; use Illuminate\Database\Schema\Blueprint; use Illuminate\Support\Facades\Schema; return new class extends Migration { public function up(): void { Schema::create('tags', function (Blueprint $table) { $table->id(); $table->string('name'); // Add other columns as needed $table->timestamps(); }); } public function down(): void { Schema::dropIfExists('tags'); } }; For the posts table migration: use Illuminate\Database\Migrations\Migration; use Illuminate\Database\Schema\Blueprint; use Illuminate\Support\Facades\Schema; return new class extends Migration { public function up(): void { Schema::create('posts', function (Blueprint $table) { $table->id(); $table->string('title'); $table->string('content')->nullable(); // Add other columns as needed $table->timestamps(); }); } public function down(): void { Schema::dropIfExists('posts'); } }; For the videos table migration: use Illuminate\Database\Migrations\Migration; use Illuminate\Database\Schema\Blueprint; use Illuminate\Support\Facades\Schema; return new class extends Migration { public function up(): void { Schema::create('videos', function (Blueprint $table) { $table->id(); $table->string('title'); // Add other columns as needed $table->timestamps(); }); } public function down(): void { Schema::dropIfExists('videos'); } }; For the pivot table migration (taggables): use Illuminate\Database\Migrations\Migration; use Illuminate\Database\Schema\Blueprint; use Illuminate\Support\Facades\Schema; return new class extends Migration { public function up(): void { Schema::create('taggables', function (Blueprint $table) { $table->id(); $table->unsignedBigInteger('tag_id'); $table->unsignedBigInteger('taggable_id'); $table->string('taggable_type'); }); } public function down(): void { Schema::dropIfExists('taggables'); } }; Step 2: Create the Models Create the models for Tag, Post, and Video using the Artisan command: php artisan make:model Tag php artisan make:model Post php artisan make:model Video Step 3: Define the Many-to-Many Polymorphic Relationship A Many-to-Many Polymorphic Relationship is defined by using the morphToMany() method on the models that can have tags (like Post and Video) and the morphedByMany() method on the Tag model. Define the relationships as follows: For the Tag model: namespace App\Models; use Illuminate\Database\Eloquent\Model; class Tag extends Model { protected $fillable = ['name']; public function posts() { return $this->morphedByMany(Post::class, 'taggable'); } public function videos() { return $this->morphedByMany(Video::class, 'taggable'); } } For the Post model: namespace App\Models; use Illuminate\Database\Eloquent\Model; class Post extends Model { protected $fillable = ['title', 'content']; public function tags() { return $this->morphToMany(Tag::class, 'taggable'); } } For the Video model: namespace App\Models; use Illuminate\Database\Eloquent\Model; class Video extends Model { protected $fillable = ['title']; public function tags() { return $this->morphToMany(Tag::class, 'taggable'); } } Step 4: Creating Records Now, you can create and retrieve records with Many-to-Many Polymorphic Relationships: // Creating tags $tag1 = Tag::create(['name' => 'Laravel']); $tag2 = Tag::create(['name' => 'PHP']); $tag3 = Tag::create(['name' => 'Database']); // Creating posts $post1 = Post::create([ 'title' => 'Introduction to Laravel', 'content' => '...' ]); $post2 = Post::create([ 'title' => 'Laravel Best Practices', 'content' => '...' ]); // Creating videos $video1 = Video::create([ 'title' => 'Laravel Tutorial' ]); $video2 = Video::create([ 'title' => 'Advanced PHP Concepts' ]); // Attaching tags to posts and videos $post1->tags()->attach([$tag1->id, $tag2->id]); $post2->tags()->attach([$tag1->id, $tag3->id]); $video1->tags()->attach([$tag1->id, $tag2->id]); $video2->tags()->attach([$tag2->id, $tag3->id]); After we ran this code our database will contain the following data: MySQL Command Line Client Showing Tables posts, videos, tags and taggables Step 5: Retrieving Records // Retrieving tags for a post $post = Post::find(1); $tags = $post->tags; // Retrieving posts for a tag $tag = Tag::find(1); $posts = $tag->posts; // Retrieving tags for a video $video = Video::find(1); $tags = $video->tags; // Retrieving videos for a tag $tag = Tag::find(2); $videos = $tag->videos; Further Examples of Many-To-Many Polymorphic Relationships Parent Model 1Parent Model 2Child ModelPolymorphic RelationshipUserRolePermissionpermissionableArticleCategoryTagtaggableProjectTeamMemberskillableDocumentVideoViewerviewableTable Showing Example Models Which Can Have a Many-To-Many Polymorphic Relationship Conclusion In this blog post, we explored Many-to-Many Polymorphic Relationships in Laravel, which allow for flexible associations between multiple models using a single pivot table. We discussed how to set up the relationships and perform operations such as creating and retrieving records. By understanding Many-to-Many Polymorphic Relationships, you can build more versatile and dynamic applications in Laravel. Happy coding! References Laravel Eloquent Relationships Laravel Migrations

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