In recent years, several new database technologies emerged that are not RDBMS. Most, if not all of them, tried to solve a particular problem (instead of wanting to be a generic solution for everybody). They are collectively called NoSQL databases. The NoSQL part can be interpreted in two ways: NO SQL, meaning no query language available, or Not Only SQL, meaning the technology supports more than just SQL. NoSQL databases have become quite popular in web development.

There are several types. The group of NoSQL databases that is of interest to us are so-called document databases. What is stored in the database are documents. A document in this context is not, let's say, a Word or PDF document, but a JSON object. Document databases provide the ability to query on any field in the document, so they are, for sure, Not Only SQL databases.

What we are doing here is the reverse of what is going on with RDBMS. Every record, or document, will contain all the information we want in it...