Introducing the Data Set

To introduce you to the various methods of accessing data, all the data used for examples in this chapter comes from the same data set. The data set is a collection that contains information about 5,000 words. This provides a large enough data set to implement the necessary examples.

You can create the data set on your development system by executing the ch15/generate_data.js script provided in the code archive for this book. The generate.js script is a basic JavaScript MongoDB shell script that will create a database named words and a collection named word_stats. To run the script, download the generate_data.js file from the book’s code archive to your local system, start MongoDB, and execute the following command from a console prompt in the same directory as the script file:

mongo generate_data.js

The structure of objects in this data set is as follows and should be fairly intuitive (which is why it was selected):

Click here to view code image

{
  word: <word>,
  first: <first_letter>,
  last: <last_letter>,
  size: <character_count>,
  letters: [<array_of_characters_in_word_no_repeats>],
  stats: {
    vowels:<vowel_count>, consonants:<consonant_count>},
  charsets: [
    {
      "type": <consonants_vowels_other>,
      "chars": [<array_of_characters_of_type_in_word>]},
    . . .
  ],
}

This document structure includes fields that are strings, integers, arrays, subdocuments, and arrays of subdocuments.