Executing Simple Queries

Now that we have connected to MongoDB, we can run some simple queries against the database. Running queries in the Node.js driver is very similar to running queries in the shell. By now, you should be familiar with the find command in the shell:

db.movies.findOne({})

Here is the syntax for the find command in the driver:

collection.find({title: 'Blacksmith Scene'}).each(function(err, doc) { … }

As you can see, the general structure is the same as the find command you would execute in the mongo shell. Here, we get a collection from the database object, and then we run the find command against that collection with a query document. The process itself is straightforward. The main differences concern how we structure our commands and how we handle the results returned from the driver.

When writing Node.js applications, one of the critical concerns is to ensure that your code is written in such a way that it can be modified, extended...