Day 5: FastAPI CRUD APIs with Validations

After migrating my project to PostgreSQL, the next step was to make the API truly useful: enabling Create, Read, Update, and Delete (CRUD) operations with proper validations. This milestone turns the service into a complete backend system that can manage user data safely and reliably.

🔑 Key Concepts

• CRUD Operations: Every production API needs endpoints to create, retrieve, update, and delete resources. Together, they form the lifecycle of data management.
• Pydantic Validations: FastAPI integrates with Pydantic to validate request payloads. This ensures that inputs (like email addresses or names) are checked before hitting the database, preventing errors and improving reliability.

🛠 Hands‑On Progress

I implemented a full set of CRUD endpoints for the User model:

• POST /users/ → Create a new user with validated input.
• GET /users/ → Retrieve all users.
• GET /users/{id} → Fetch a single user by ID.
• PUT /users/{id} → Update user details with validation.
• DELETE /users/{id} → Remove a user from the database.

Each endpoint uses SQLAlchemy ORM for database operations and Pydantic schemas for input/output validation.

💡 Reflection

This step elevated the project from a simple demo into a functional backend service.

• CRUD endpoints make the API practical for real applications.
• Validations ensure data integrity and protect against invalid inputs.

👉 [Link to GitHub repo]

🔮 What’s Next

Day 6 will focus on pytest unit tests to automate validation of these endpoints. Testing discipline is essential for reliability engineering, and adding tests will strengthen the portfolio further.