How to create Eloquent model with relationship?

Developing efficient applications often requires you to manage several entities, their relationships, and the data they contain. Laravel's Eloquent model is a powerful tool that provides an object-oriented interface for working with database tables. In this post, we will focus on creating Eloquent models with their corresponding relationship in a more beautiful and streamlined manner using Laravel.

Setting Up the Database Tables

Firstly, let's set up our two database tables: "Person" for storing person-related data (firstname and lastname) and "Employee" to store employee details (position). The database schema could look like this:

CREATE TABLE persons (
   id SERIAL PRIMARY KEY,
   firstname VARCHAR(255),
   lastname VARCHAR(255)
);

CREATE TABLE employees (
   id INT NOT NULL AUTO_INCREMENT,
   person_id INT,
   position VARCHAR(100),
   FOREIGN KEY (person_id) REFERENCES persons(id)
);

Creating the Models

Now let's create an "Employee" Eloquent model that inherits from Laravel's Model class and includes the necessary columns. The Person model can be created in a similar way:

class Employee extends Model {
   protected $fillable = ['firstname', 'lastname', 'position'];

   // Define relationships with the Person model here, if needed
}

In this example, we've defined a few columns that can be filled when creating an employee: firstname, lastname, and position. The $fillable property ensures these fields are mass assignable. Note that we haven't included any relationship definition yet for the Employee model.

Creating Eloquent Model with Relationship

To create an instance of the Employee model (including its related person) in a more beautiful way, we can utilize Eloquent relationships' 'create' method:

use App\Person; // Import Person model here
use App\Employee; // Import Employee model here

// Create new employee and associate it with the created person instance:
$person = new Person();
$person->firstname = 'Jack';
$person->lastname = 'London';
$person->save(); // Save first person record

$employee = new Employee();
$employee->position = 'writer';
$employee->person_id = $person->id;
$employee->save(); // Save employee instance, linking with the person

Here, we first create a Person object and save it to our database. Then, we create an Employee object while specifying the relationship (via 'person_id'). The 'person_id' is set to the ID of the previously saved Person instance. In conclusion, this approach allows you to create Eloquent models with relationships in a more aesthetically pleasing and efficient manner that keeps your code clean and maintainable. For more information on working with Laravel's Eloquent ORM, check out our detailed tutorial at Laravel Company.