Model Change with Changesets

Ecto changesets

Changesets are policies for changing data, and they fulfill these roles:

• Changesets cast unstructured user data into a known, structured form to ensure data safety. The most common structure is an Ecto database schema.

• Changesets capture differences between safe, consistent data and a proposed change, allowing efficiency.

• Changesets validate data using known consistent rules, ensuring data consistency.

• Changesets provide a contract for communicating error states and valid states, ensuring a common interface for change.

We can see changesets in action in the Product.changeset/2 function in pento/lib/pento/catalog/product.ex: