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Developer tools · #ecto
Learn how to use Ecto Changesets to prevent mass-assignment vulnerabilities by implementing strict data casting and separating application validation from database constraints.
Learn how Ecto Changesets prevent data corruption by decoupling input casting and validation from database persistence in Elixir.
Ecto.Multi lets you chain inserts, updates, and custom callbacks into a single all‑or‑nothing transaction. This guide shows a concrete example, explains how it works, and lists common pitfalls and verification steps.
Learn how Ecto.Multi lets you compose multiple database operations into an atomic transaction, handle errors cleanly, and avoid common side‑effect pitfalls in Elixir apps.
In a Phoenix project the config/dev.exs file uses config :my_app, MyApp.Repo, url: \"postgres://localhost/my_app_dev\" and the app runs fine locally. In production I switch to a release and change the config to config :my_app, MyApp.Repo, url: System.get_env(\"DATABASE_URL\") . The release starts but the database connection fails, even though DATABASE_URL is
An Elixir application using Ecto with PostgreSQL needs to store all timestamps as UTC via :utc_datetime / timestamptz while accepting and presenting values in a per-user regional time zone. tzdata is available for Calendar.DateTime.shift_zone/3. Ecto does not perform automatic regional conversion. The documented pattern is UTC storage in the database with co
Goal: ensure that a failed Ecto upgrade can be recovered safely when a migration contains irreversible operations such as raw SQL or data transforms. Constraint: the change/0 callback can auto‑reverse only a limited set of commands; any irreversible step raises on rollback, while explicit up/0/down/0 pairs give full control but require more code and duplicat
Ecto + PostgreSQL: Schema Drift Detection After Restore When a PostgreSQL database is restored from a pg_dump archive, the application’s Ecto schema modules may no longer match the on‑disk structure. The migrations table can become out of sync if the backup predates recent migrations, leading to runtime errors or data inconsistencies. Currently, Ecto offers
Goal: Assess whether Ecto can guarantee that a migration’s down function restores the database to its pre‑migration state after a schema change Ecto runs each migration inside a single transaction, but the generated down callback does not automatically undo data modifications that occur before the schema alteration. Certain schema operations—such as changing
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