rules.md

Usage Rules

IMPORTANT: Consult these usage rules early and often when working with the packages listed below. Before attempting to use any of these packages or to discover if you should use them, review their usage rules to understand the correct patterns, conventions, and best practices.

phoenix:ecto usage

Ecto Guidelines

• Always preload Ecto associations in queries when they'll be accessed in templates, ie a message that needs to reference the message.user.email
• Remember import Ecto.Query and other supporting modules when you write seeds.exs
• Ecto.Schema fields always use the :string type, even for :text, columns, ie: field :name, :string
• Ecto.Changeset.validate_number/2 DOES NOT SUPPORT the :allow_nil option. By default, Ecto validations only run if a change for the given field exists and the change value is not nil, so such as option is never needed
• You must use Ecto.Changeset.get_field(changeset, :field) to access changeset fields
• Fields which are set programatically, such as user_id, must not be listed in cast calls or similar for security purposes. Instead they must be explicitly set when creating the struct
• Always invoke mix ecto.gen.migration migration_name_using_underscores when generating migration files, so the correct timestamp and conventions are applied