Database & Data Modeling

This micro-service uses MongoDB as its primary data store and Mongoose as the Object Data Modeling (ODM) library.

Why MongoDB?

MongoDB is a NoSQL, document-oriented database that offers:

Flexibility: We can easily change the data structure without complex migrations.
Scalability: Designed for horizontal scaling.
Performance: High-speed read/write operations for many common use cases.

Mongoose Integration

Mongoose provides a straight-forward, schema-based solution to model your application data. It includes built-in type casting, validation, query building, and business logic hooks.

Schema Definition

Our main data model is defined in src/models/Part.js:

const partSchema = new mongoose.Schema({
  name: { type: String, required: true },
  category: { type: String, required: true },
  price: { type: Number, required: true },
  stock: { type: Number, required: true },
  description: String,
  createdAt: { type: Date, default: Date.now },
});

Connection Management

The database connection is managed in src/db.js. It includes:

Environment Variable Support: Uses MONGODB_URI for configuration.
Connection Logic: Wraps mongoose.connect() and provides feedback on connection success or failure.
Testability: Allows passing a dynamic URI to support integration tests (e.g., Testcontainers).

Data Persistence in Docker

In our docker-compose.yml, we define a named volume for MongoDB to ensure that data persists even if the container is removed:

volumes:
  mongodb_data: