Repository pattern in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the Repository pattern?

The Repository pattern is a way to separate data access logic from business logic. It acts like a middleman between your app and the database, making code easier to manage and test.

beginner

Why use the Repository pattern in PHP?

Using the Repository pattern helps keep your code clean by hiding database details. It also makes switching databases easier and improves testing by allowing you to mock data sources.

intermediate

What is the main role of a Repository interface?

A Repository interface defines the methods for data operations like add, find, update, and delete. It sets a contract that any repository class must follow.

intermediate

How does the Repository pattern improve testing?

It allows you to replace the real database with fake data sources during tests. This makes tests faster and more reliable because they don't depend on a real database.

beginner

Show a simple example of a Repository interface method in PHP.

Example: <pre>interface UserRepository {
    public function findUserById(int $id): ?User;
}</pre> This method finds a user by their ID or returns null if not found.

What does the Repository pattern mainly help with?

A Improving user interface design

B Encrypting data in the database

C Separating data access from business logic

D Managing server configurations

The Repository pattern separates data access logic from business logic to keep code organized.

Which of these is a benefit of using the Repository pattern?

A Makes switching databases easier

B Slows down application performance

C Requires more database queries

D Removes the need for testing

The Repository pattern hides database details, making it easier to switch databases.

What does a Repository interface define?

A Server connection settings

B User interface layout

C CSS styles for the app

D Methods for data operations like add, find, update, delete

A Repository interface defines the methods for data operations.

How does the Repository pattern help with testing?

A Allows replacing real database with fake data sources

B Automatically writes test cases

C Runs tests faster by skipping logic

D Prevents any bugs in code

It allows tests to use fake data sources instead of a real database.

Which PHP code snippet shows a Repository interface method?

A echo 'Hello World';

B public function findUserById(int $id): ?User;

C $db->connect();

D class User {}

This method signature is typical for a Repository interface.

Explain the Repository pattern and why it is useful in PHP applications.

Think about how your app talks to the database and how the Repository acts as a middleman.

Describe how you would create a Repository interface and implement it for a User entity in PHP.

Start with the contract (interface), then write the class that follows it.