“Northwind Elixir Traders” updated: uniqueness constraints with SQLite

Another chapter of the “Northwind Elixir Traders” book has been released, this time on uniqueness constraints, including new lessons on the ramifications of using SQLite with Ecto–and how we can maintain compatibility with PostgreSQL, regardless.

Next to the new chapter, here are some other changes:

• Amended the first chapter with a discussion of supervision trees and the content of application.ex that mix new northwind_elixir_traders –sup generates, so that we can use the Ecto Repo.
• Edits for readability, typos and clarifications across all already-released chapters.

The next chapter will tackle the first associations between tables of the Northwind Traders database schema, as we inch closer to the more-complex center of the database’s ERD, with the ultimate goal of modeling the Many-to-Many relationship between orders and products in the OrderDetails table. But, first: has_many and belongs_to!

BTW, this is the ERD that we are modeling with Ecto in an SQLite3 database: Northwind Traders on dbdiagram.io

• The book is available as PDF and ePub on Leanpub
• Join the discussion on elixirforum.com