Ecto Patterns

Expert guidance for database operations, data validation, and query composition with Ecto.

Core Principles

• Ecto is not an ORM — it's a toolkit for data mapping and validation
• Changesets are for validation AND tracking changes, not just database inserts
• Queries are composable data structures, not method chains on models
• Separate read and write concerns
• Use the database as the source of truth

Changesets

Validation Outside the Database

Use embedded schemas and changesets for validating data that never touches the DB: