Entities and the id

An entity is a kind of stored record with a lasting identity, like a table with types. Each one is declared in its own file under its domain's entities/ folder. A domain is one business area of your app, here planning.

domains/planning/entities/project.jadpo:

type ProjectName = Text {    max_length: 80}/// A group of todos with a shared goal.entity Project {    id: Uuid  // version 7, generated on create    name: ProjectName}

Text and Uuid are built in. Project and ProjectName are yours, and a type only this file uses lives in this file.

Every entity's identity is one field, id, based on Uuid. Jadpo generates it as a version 7 UUID when the record is created, or as the version its named type pins, and callers never supply it. Other code refers to the field as Project.id.

There is no compound identity. A link between two entities is an entity of its own, with its own id and a unique rule over the two references.

An entity value is a snapshot that never changes: reading one of its fields never touches the database.