Laravel 10 one to many Relationship Example

In the realm of web development, building data-driven applications often involves establishing intricate relationships between different elements in a database. As a Laravel developer, I have come to appreciate the power of this PHP framework, which offers an array of powerful tools for managing these relationships efficiently.

Among the various types of relationships supported by Laravel, I find the one-to-many relationship particularly versatile and fundamental. In this article, I would like to share my exploration of the one-to-many relationship through a practical example, where we will focus on two essential tables: "articles" and "comments."

For one to many relationship use can use hasMany and belongsTo method in the model for access to each other model.

Understanding and implementing the one-to-many relationship is a crucial skill for developers like me who aim to create robust and scalable web applications.

By mastering this relationship type, I can efficiently manage related data, optimize database queries, and present information in a structured and user-friendly manner.

Throughout this article, I will guide you through the process of setting up a Laravel project, creating database migrations for the "articles" and "comments" tables, generating models, and defining the one-to-many relationship between these two tables.

Together, we will explore how to establish relationships between records, access related data, and leverage the power of Laravel's Eloquent ORM to navigate through these connections effortlessly.

Whether you are a seasoned Laravel developer or a newcomer eager to explore the intricacies of database relationships, this article is designed to empower you with the knowledge and hands-on experience to confidently implement one-to-many relationships in your Laravel applications.

So, let's embark on this enlightening journey together and unlock the potential of the one-to-many relationship in Laravel

 

In this step, we will create migrations for the "articles" and "comments" tables, enabling us to define their respective structures and relationships. Additionally, we will establish a foreign key constraint within the "articles" table to facilitate the one-to-many relationship with the "comments" table.

Create Migration for Articles Table

Schema::create('articles', function (Blueprint $table) {

    $table->increments('id');

    $table->string('name');

    $table->string('slug');

    $table->timestamps();

});

Create Migration for Comments Table with Foreign Key

Schema::create('comments', function (Blueprint $table) {

    $table->increments('id');

    $table->integer('article_id')->unsigned();

    $table->text('comments');

    $table->timestamps();

    $table->foreign('article_id')->references('id')->on('articles')->onDelete('cascade');

});

 

 

To establish the one-to-many relationship between the "articles" and "comments" tables, we need to create models for each table and define the relationship methods within them. Follow these steps to create the models and add the one-to-many relationship

Article Model:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Article extends Model
{
    /**
     * Get the comments for the article.
     */
    public function comments()
    {
        return $this->hasMany(Comment::class);
    }
}

Comment Model:

Now, that we can access all of an article's comments, let's define a relationship to allow a comment to access its parent article. To define the inverse of a hasMany relationship, define a relationship method on the child model which calls the belongsTo method.

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Comment extends Model
{
    /**
     * Get the article that owns the comment.
     */
    public function article()
    {
        return $this->belongsTo(Article::class);
    }
}

In the above example, Eloquent will attempt to find a Article a model that has an id which matches the article_id column on the Comment model. So, in this example, Eloquent will assume the Article model's foreign key on the comments table is article_id.

If the foreign key on the Comments model is not article_id, you may pass a custom key name as the second argument to the belongsTo method.

/**
 * Get the article that owns the comment.
 */
public function article()
{
    return $this->hasMany(Comment::class, 'foreign_key');
 
    return $this->hasMany(Comment::class, 'foreign_key', 'local_key');
}

 

Once the relationship is defined, we may retrieve the related record using Eloquent's dynamic properties. So, here we can use the Article model with the comments function.

$comments = Article::find(5)->comments;
 
foreach ($comments as $comment) {
    //
}

$comment = Comment::find(7);
 
$article = $comment->article->name;

 

 Now, we will add records in the comment table using the article.

$article = Article::find(1);
 
$comment = new Comment;
$comment->comments = "One To Many Exmaple";
 
$article->comments()->save($comment);

 

In all relationships, you can use conditions to query with the model.

$comment = Article::find(1)->comments()
                    ->where('name', 'techsolutionstuff')
                    ->first();

// or

// Retrieve an article along with its comments
$article = Article::find(1);
$comments = $article->comments;

// Retrieve a comment and its associated article
$comment = Comment::find(1);
$article = $comment->article;

 

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