Bulk Product Import Service

Build a data import service using SQLAlchemy that bulk-imports product records from CSV data into PostgreSQL.

Domain

• Category: name (unique)
• Product: name, sku (unique), price_cents, belongs to a category

Requirements

Produce Python files in a src/ directory:

• src/database.py -- engine configuration, session factory, Base class, and session dependency
• src/models.py -- Category and Product ORM models
• src/importer.py -- an import_products(db, rows) function that takes a list of dicts, each with keys name, sku, price_cents, and category_name. For each row:
  • Find or create the category by name
  • Insert the product into that category
  • The function may receive thousands of rows, so it should be efficient
  • If a product with the same SKU already exists, skip it and continue with the next row

No test files, no migration files, no API framework code.