Repository pattern for data access in Express - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the Repository pattern in data access?

It is a way to organize code so that data access logic is separated from business logic. It acts like a middleman between the app and the database, making code easier to manage and test.

beginner

Why use the Repository pattern in an Express app?

It helps keep your routes and controllers clean by moving database queries to a separate place. This makes your app easier to read, maintain, and change later without breaking other parts.

intermediate

How does the Repository pattern improve testing?

Since data access is in one place, you can easily replace it with fake data or mocks during tests. This means you can test your app logic without needing a real database.

beginner

In Express, what does a typical Repository file contain?

It usually has functions like find, create, update, and delete that talk to the database. These functions are called by controllers to get or change data.

intermediate

What is a benefit of changing the database technology when using the Repository pattern?

You only need to update the repository code, not the whole app. This makes switching databases easier and safer.

What role does the Repository pattern play in an Express app?

A Separates data access from business logic

B Handles user authentication

C Manages server configuration

D Renders HTML views

The Repository pattern separates data access code from the rest of the app logic.

Which function would you expect in a Repository file?

A renderView()

B handleRequest()

C findUser()

D startServer()

Repository files contain functions like findUser() to get data from the database.

How does the Repository pattern help with testing?

A By making the UI prettier

B By encrypting data

C By speeding up server startup

D By allowing database code to be mocked easily

It allows replacing real database calls with mocks during tests.

If you switch from MongoDB to MySQL, what part of the app changes with the Repository pattern?

A Only the repository code

B All route handlers

C All frontend code

D Server configuration only

Only the repository code needs updating to handle the new database.

Which is NOT a benefit of using the Repository pattern?

A Cleaner code organization

B Faster HTTP response times

C Easier database switching

D Simpler testing

The Repository pattern improves code structure and testing but does not directly speed up responses.

Explain how the Repository pattern separates concerns in an Express app.

Think about who talks to the database and who handles app logic.

Describe how using the Repository pattern makes testing easier.

Consider how you avoid using the real database in tests.