Creating Models and Migrations

Welcome back. 0:00 We created our models using the php artisan make:model command 0:01 with the handy-m flag to create both a model and migration at the same time. 0:06 Next, we're going to connect our tables to our models using the Eloquent 0:14 relationships for our authors and books inside of the app directory. 0:19 For example, if an author has several books, then using Eloquent 0:25 relationship allows us to display all of the books by a specific author. 0:30 Let's get started. 0:35 First, let's navigate to the app directory and open the authors'.php model and 0:38 assign a variable using the protected access modifier like this. 0:44 This command is not necessary because Laravel automatically makes a connection 0:49 from the plural authors' table to the singular author model. 0:54 The reason we're using this command is to be explicit about what is happening here. 0:59 Otherwise, they would be, well, invisible. 1:04 So let's keep it for clarity's sake. 1:07 Next, let's define the relationship between authors and books like this. 1:10 When we add the public function, Laravel looks at the model defining the migration 1:35 and notices that we have an author_id column inside of the database table. 1:41 Laravel then makes the connection that $this author, singular, has many books. 1:48 Assuming that the author has more than one book, of course. 1:54 You may be asking yourself, if defining authors is optional. 1:59 Why are we covering this? 2:03 Which is a great question. 2:05 Imagine we have a database that was pre-built for 2:07 us without using this best practice. 2:10 In such a case, we would need to be explicit and 2:13 define the relationship using the foreign key and local key in your application. 2:16 Since we're building the database using best practices, 2:23 we can keep our code minimal. 2:27 To learn more about foreign keys and local keys, check out the teacher's notes below. 2:29 Next, let's define the book model and follow the same best practices. 2:36 As we discussed, we don't need to define the dollar table as 2:41 books because it's the plural of the book model. 2:44 But I like to be explicit when building models. 2:48 So let's use protected $table = 'books' like we did in the author model. 2:51 The same explicit relationship applies to the inverse relation of books 2:57 that belong to authors. 3:02 Remember, the book model will look for 3:08 an ID that belongs to author which is defined in the table as author_id. 3:11 Now that our relationships are defined, let's head over to our author and 3:20 book models to add the final touches by specifying which fields are changeable. 3:25 Protected access modifier fields, 3:31 by default are protected from mass assignment. 3:34 But we can assign columns that we want to change or 3:38 define as fillable such as name, title, company and email. 3:42 It's also worth mentioning that we wouldn't want to 3:49 use protected $fillable for 3:52 users with passwords because we wouldn't typically want to mass assign passwords. 3:54 Instead, we would enter them individually. 4:00 We could use $hidden to hide fields from displaying a password in the API response, 4:03 which we won't use in this course, but it's important to keep in mind. 4:09 Next, let's head over to the author.php file and add the name, title, 4:13 company and email, so we can specify them as fillable inside of an array like this 4:19 Notice that I didn't include ID. 4:42 Including ID as fillable would cause errors for 4:45 the consumer of the API because Laravel automatically assigns an ID for us. 4:49 Finally, let's head 4:55 over to the book model and 5:00 add $fillable 5:07 fields like this. 5:11 Sweet, we can now mass assign books and 5:24 authors columns in our database tables connected to our models. 5:27 Nice job, our Eloquent relationships are defined as specific 5:32 column fields, which is to say they're changeable. 5:37 To learn more about mass assignment, protected $fillable, and 5:43 how to avoid duplicate unique IDs, check the teacher’s notes below. 5:47 In the next section, we'll dive into factories and seeders to quickly add 5:52 test data for application using the powerful Faker library. 5:57 See you there. 6:02