OeditusCredo.Check.Warning.MissingPreload (OeditusCredo v0.6.0)

Basics

This check has a base priority of normal and works with any version of Elixir.

Explanation

Missing preload in Ecto queries can lead to N+1 query problems.

When fetching associations, use preload to fetch them efficiently in a single query.

Bad:

users = Repo.all(User)
# Later accessing user.posts will trigger N+1 queries

Good:

import Ecto.Query
users = User |> preload(:posts) |> Repo.all()

Check-Specific Parameters

Use the following parameters to configure this check:

:exclude_test_files

Set to true to skip test files (default: false)

This parameter defaults to nil.

General Parameters

Like with all checks, general params can be applied.

Parameters can be configured via the .credo.exs config file.