🚀 FastAPI User Management System

This is a User Management API built with FastAPI, SQLAlchemy, and PostgreSQL. The API allows you to create, read, and delete users, following best practices such as data validation with Pydantic, database session management, and dependency injection.

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📌 Features

✅ CRUD Operations – Create, Read, and Delete users
✅ Database Integration – PostgreSQL with SQLAlchemy ORM
✅ Pydantic Validation – Ensures proper data validation
✅ Dependency Injection – Efficient database session management
✅ Exception Handling – Returns meaningful error messages
✅ Modular Structure – Organized codebase for maintainability

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🛠️ Setup & Installation

1. Clone the Repository

git clone https://github.com/gideon877/fastapi-user-management.git
cd fastapi-user-management

2. Create a Virtual Environment

python -m venv venv
source venv/bin/activate  # On Windows use `venv\Scripts\activate`

3. Install Required Packages

pip install fastapi uvicorn sqlalchemy databases pydantic psycopg psycopg2-binary python-dotenv

4. Set Up Environment Variables

Create a .env file and add your PostgreSQL database URL:

DATABASE_URL=postgresql://username:password@localhost/dbname

5. Run the API

uvicorn main:app --reload

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📂 Project Structure

📂 fastapi-user-management
 ┣ 📜 main.py          # FastAPI app with API endpoints
 ┣ 📜 model.py         # SQLAlchemy database models
 ┣ 📜 schema.py        # Pydantic schemas for validation
 ┣ 📜 services.py      # Business logic and database operations
 ┣ 📜 database.py      # Database connection and session management
 ┣ 📜 .env             # Environment variables
 ┗ 📜 README.md        # API Documentation

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🚀 API Endpoints

1️⃣ Create a New User

POST /users/
Creates a new user.

Request Body (JSON)

{
  "first_name": "John",
  "last_name": "Doe",
  "age": 25,
  "gender": "Male",
  "race": "Caucasian"
}

Response

{
  "id": 1,
  "first_name": "John",
  "last_name": "Doe",
  "age": 25,
  "gender": "Male",
  "race": "Caucasian"
}

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2️⃣ Get All Users

GET /users/
Fetches a paginated list of users.

Query Parameters

• skip (default: 0) → Number of records to skip
• limit (default: 10) → Number of records to return

Response

[
  {
    "id": 1,
    "first_name": "John",
    "last_name": "Doe",
    "age": 25,
    "gender": "Male",
    "race": "Caucasian"
  },
  {
    "id": 2,
    "first_name": "Jane",
    "last_name": "Smith",
    "age": 30,
    "gender": "Female",
    "race": "Asian"
  }
]

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3️⃣ Get a User by ID

GET /users/{user_id}
Fetches details of a single user.

Example Request:

GET /users/1

Response:

{
  "id": 1,
  "first_name": "John",
  "last_name": "Doe",
  "age": 25,
  "gender": "Male",
  "race": "Caucasian"
}

Error Response:

{
  "detail": "User not found"
}

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4️⃣ Delete a User

DELETE /users/{user_id}
Deletes a user by ID.

Example Request:

DELETE /users/1

Response:

{
  "message": "User deleted successfully"
}

Error Response:

{
  "detail": "User not found"
}

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📌 Future Enhancements

✅ Add filters and statistics (e.g., most common names, average age)
✅ Implement user update functionality
✅ Add authentication and authorization

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❤️ Contributing

Feel free to open issues and submit pull requests. Let's build something great together!

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📜 License

This project is licensed under the MIT License.