4 Ways to Define Model in Eloquent (Laravel)

Introduction

Laravel’s Eloquent ORM provides an elegant way to interact with databases. Here, we will explore different ways to define models using Eloquent, diving into a range of solutions fitting various scenarios.

Approach 1: Basic Model Creation

Defining a simple model linked to a database table:

1. Create a new model using the artisan command php artisan make:model ModelName.
2. Edit the generated model file to fit your needs.
3. If necessary, set the $table property if the table name does not follow Laravel’s naming convention.

Example:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class ModelName extends Model
{
    protected $table = 'custom_table_name';
}

This creates a basic model. Laravel assumes the table name by pluralizing the class name unless you specify otherwise.

Approach 2: Defining Relationships

Use models to define relationships between database tables:

1. Define methods within the model reflecting the relationships (e.g., one-to-one, one-to-many).
2. Use Eloquent relationship functions, such as hasOne, hasMany, belongsTo, and belongsToMany.
3. Return the result of the relationship function within your method.

Example:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class User extends Model
{
    public function posts()
    {
        return $this->hasMany(Post::class);
    }
}

This provides a way to easily retrieve related models.

Approach 3: Accessors & Mutators

Define custom attribute getters and setters to modify model data:

1. Create methods prefixed with get to define an accessor or set for a mutator.
2. Follow the method name with the attribute name in StudlyCase followed by Attribute.
3. For accessors, return the modified attribute. For mutators, modify the attribute’s value directly.

Example:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class User extends Model
{
    public function getFullNameAttribute()
    {
        return $this->attributes['first_name'] . ' ' . $this->attributes['last_name'];
    }

    public function setFirstNameAttribute($value)
    {
        $this->attributes['first_name'] = strtolower($value);
    }
}

Accessors and mutators allow you to manipulate model data on-the-fly.

Approach 4: Global Scopes

Apply a query scope to all queries for a model:

1. Create a new class implementing the Scope interface.
2. Define an apply method within it.
3. Attach the scope to a model using the addGlobalScope method.

Example:

<?php

namespace App\Scopes;

use Illuminate\Database\Eloquent\Scope;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Builder;

class AgeScope implements Scope
{
    public function apply(Builder $builder, Model $model)
    {
        $builder->where('age', '>', 18);
    }
}

// In your model

namespace App\Models;

use App\Scopes\AgeScope;
use Illuminate\Database\Eloquent\Model;

class User extends Model
{
    protected static function booted()
    {
        static::addGlobalScope(new AgeScope);
    }
}

Global scopes affect how models are retrieved across the whole application.

Conclusion

Defining models in Laravel’s Eloquent can be approached from various angles. Simple models are a breeze with Laravel’s naming conventions, while relationships provide robust methods to interact with related data. Accessors and mutators grant fine-tuned control over data access and manipulation, and global scopes offer a way to enforce a common query constraint. Clearly understanding these methods paves the way for an organized and efficient database integration within your application.