Reads and writes

How a program reads and changes stored records: named queries, filters, order and pages, totals, related records, the operations every entity gets, what a refused write reports, and how an action stays all-or-nothing while other requests change the same records. Where records are stored, and how caches copy them, is on Data; who may read or change them is on Policy.

The examples follow the golden todo app's planning domain: User, Project and Todo. Each example marked check compiles with this checkout's jadpo, and its tests run against PostgreSQL. What isn't built yet is listed in What is built.