Practical Microservices

Reading a Stream’s Messages

Now let’s get the messages in a particular stream. We’re going to support three classes of streams, namely, entity, category, and the $all stream. As a refresher, entity streams are usually named something like identity-721304b9-8ece-4c1c-aaed-efad4886023d—a category followed by a UUID. The events in this example entity stream are also in the identity category stream. $all is a stream containing every message in the store.

Eventide provides us with functions for entity and category streams. We’ll write our own query for the $all stream when we get to Chapter 13, ​Debugging Components​.

Stream Type	SQL Snippet
Category	SELECT * FROM get_category_messages($1, $2, $3)
Non-category	SELECT * FROM get_stream_messages($1, $2, ...