Laravel Many to Many Polymorphic Relationship Example

This is the sixth & last blog post of Laravel relationship Model tutorial series. In this tutorial, we are going to learn how to implement Many to Many Polymorphic relationship within our Laravel application. Imagine that, If we have posts, videos, and tag tables, and we require to connect with each other with your requirement like every post have multiple tags and same for videos too. Also every tag many are connected with multiple post or multiple videos too. But we can easily do it using just one table "taggables". Just read the article and you got it.

Prerequisites

Laravel

To Continue with this tutorial, you should have installed Laravel in your pc. If you are still not installed Laravel in your machine you can configure it from here.

Setting up the Project

First you need to create a new laravel project by running below command in your terminal

composer create-project laravel/polymorphic-example

Then navigate to your project directory by using below command in your terminal

cd polymorphic-example

In here we will use “morphToMany()” and “morphedByMany()” relations.

Create Migration

Now we have to create migration of "posts", "videos", "tags" and "taggables" tables.

Posts table migration

Schema::create('posts', function (Blueprint $table) {
    $table->increments('id');
    $table->string("name");
    $table->timestamps();
});

Videos table migration

Schema::create('videos', function (Blueprint $table) {
    $table->increments('id');
    $table->string("name");
    $table->timestamps();
});

Tags table migration

Schema::create('tags', function (Blueprint $table) {
    $table->increments('id');
    $table->string("name");
    $table->timestamps();
});

Taggables table migration

Schema::create('taggables', function (Blueprint $table) {
    $table->integer("tag_id");
    $table->integer("taggable_id");
    $table->string("taggable_type");
});

Create Models

Now we need to create Post, Video and Comment model. we will also use "morphToMany()" and "morphedByMany()" for relationship of both model.

Post Model:

<?php
 
namespace App;
use Illuminate\Database\Eloquent\Model;
 
class Post extends Model
{
    public function tags()
    {
        return $this->morphToMany(Tag::class, 'taggable');
    }
}

Video Model:

<?php
 
namespace App;
 
use Illuminate\Database\Eloquent\Model;
 
class Video extends Model
{
    public function tags()
    {
        return $this->morphToMany(Tag::class, 'taggable');
    }
}

Tag Model:

<?php
 
namespace App;
 
use Illuminate\Database\Eloquent\Model;
 
class Tag extends Model
{
    public function posts()
    {
        return $this->morphedByMany(Post::class, 'taggable');
    }

    public function videos()
    {
        return $this->morphedByMany(Video::class, 'taggable');
    }
}

Retrieve Records

$post = Post::find(1);	
dd($post->tags);

$video = Video::find(1);	
dd($video->tags);

$tag = Tag::find(1);	
dd($tag->posts);

$tag = Tag::find(1);	
dd($tag->videos);

Create Records

$post = Post::find(1);	
$tag = new Tag;
$tag->name = "CodingtrickS.io";
$post->tags()->save($tag);

$video = Video::find(1);	
$tag = new Tag;
$tag->name = "CodingtrickS.io";
$video->tags()->save($tag);

$post = Post::find(1);	
$tag1 = new Tag;
$tag1->name = "CodingtrickS.io";
 
$tag2 = new Tag;
$tag2->name = "CodingtrickS.io 2";
$post->tags()->saveMany([$tag1, $tag2]);

$video = Video::find(1);	
$tag1 = new Tag;
$tag1->name = "CodingtrickS.io";
 
$tag2 = new Tag;
$tag2->name = "CodingtrickS.io 2";
$video->tags()->saveMany([$tag1, $tag2]);

$post = Post::find(1);	
$tag1 = Tag::find(3);
$tag2 = Tag::find(4);
$post->tags()->attach([$tag1->id, $tag2->id]);

$video = Video::find(1);	 
$tag1 = Tag::find(3);
$tag2 = Tag::find(4);
$video->tags()->attach([$tag1->id, $tag2->id]);

$post = Post::find(1);	
$tag1 = Tag::find(3);
$tag2 = Tag::find(4);
$post->tags()->sync([$tag1->id, $tag2->id]);

$video = Video::find(1);	
$tag1 = Tag::find(3);
$tag2 = Tag::find(4);
$video->tags()->sync([$tag1->id, $tag2->id])

In this tutorial, we learn how to implement many to many polymorphic relationship within Laravel. If you have any issue regarding this tutorial, mention your issue in comment section or reach me through my E-mail.