Summary

This chapter gave us an introduction to the Apache Derby RDBMS, creating a locally hosted instance with minimal setup. We then explored data models and how to codify them into a schema using DDL. We used clojure.java.jdbc to load this schema before investigating how the API allows us to perform CRUD operations, spending time on how to control the results from our query executions.

We then built an application layer for our ELO calculation application. In doing so, we learned which functions to expose as part of our API and which are internal to our application and should be kept private from a user.

In the next chapter, we'll take the public API of our application layer and learn how to build a REST-based web service to expose that API over HTTP. In this way, we can make calls from a REST client and interact with our application over a network, rather than via a locally hosted REPL.

Subsequently, we'll improve this RESTful interaction by adding a higher-level...