This is the fifth blog post of Laravel relationship Model tutorial series. In this tutorial, we are going to learn how to implement One to Many Polymorphic relationship within our Laravel application. Imagine that, If we have posts and videos tables, both need to add comments system. Then you can manage in a single table for both tables by using this One to Many Polymorphic relationship.

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
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    composer create-project laravel/polymorphic-example

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

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    cd polymorphic-example

    In here we will use morphMany() and morphTo() relations.

    Create Migration

    Now we have to create migration of "posts", "videos" and "comments" tables.
  • Posts table migration
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    Schema::create('posts', function (Blueprint $table) {
        $table->increments('id');
        $table->string("name");
        $table->timestamps();
    });
  • Videos table migration
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    Schema::create('videos', function (Blueprint $table) {
        $table->increments('id');
        $table->string("name");
        $table->timestamps();
    });
  • Comments table migration
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    Schema::create('comments', function (Blueprint $table) {
        $table->increments('id');
        $table->string("body");
        $table->integer('commentable_id');
        $table->string("commentable_type");
        $table->timestamps();
    });

    Create Models

    Now we need to create Post, Video and Comment model. we will also use morphMany()" and "morphTo()" for relationship of both model.
  • Post Model:
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    <?php
     
    namespace App;
    use Illuminate\Database\Eloquent\Model;
     
    class Post extends Model
    {
        /**
         * Get all of the post's comments.
         */
        public function comments()
        {
            return $this->morphMany(Comment::class, 'commentable');
        }
    }
  • Video Model:
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    <?php
     
    namespace App;
     
    use Illuminate\Database\Eloquent\Model;
     
    class Video extends Model
    {
        /**
         * Get all of the post's comments.
         */
        public function comments()
        {
            return $this->morphMany(Comment::class, 'commentable');
        }
    }
  • Comment Model:
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    <?php
     
    namespace App;
     
    use Illuminate\Database\Eloquent\Model;
     
    class Comment extends Model
    {
        /**
         * Get all of the owning commentable models.
         */
        public function commentable()
        {
            return $this->morphTo();
        }
    }

    Retrieve Records

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

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

    Create Records

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    $post = Post::find(1);	
    $comment = new Comment;
    $comment->body = "CodingtrickS.io";
    $post->comments()->save($comment);

    $video = Video::find(1);	
    $comment = new Comment;
    $comment->body = "CodingtrickS.io";
    $video->comments()->save($comment);

    In this tutorial, we learn how to implement one 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.