Writing and Querying MapReduce Views in CouchDB

JSON

CouchDB stores documents as JSON (JavaScript Object Notation) objects. JSON is a human-readable and lightweight data interchange format. Data structures from many programming languages can easily be converted to and from JSON. The following is an example (that will be used in Chapter 2) of a JSON object representing a book:

{
   "_id":"978-0-596-15589-6",
   "title":"CouchDB: The Definitive Guide",
   "subtitle":"Time to Relax",
   "authors":[
      "J. Chris Anderson",
      "Jan Lehnardt",
      "Noah Slater"
   ],
   "publisher":"O'Reilly Media",
   "released":"2010-01-19",
   "pages":272
}

A JSON object is a collection of key/value pairs. The book object above contains the keys and values listed in Table 1-1. JSON values can be strings, numbers, booleans (false or true), arrays (e.g., [ "J. Chris Anderson", "Jan Lehnardt", "Noah Slater" ]), null, or another JSON object.

Table 1-1. Key/value pairs in a JSON book object

Key	Value
_id	A string representing the book’s unique International Standard Book Number (ISBN)
title	A string representing the book’s title
subtitle	A string representing the book’s subtitle
authors	A JSON array of authors with each element being a string representing the author’s name
publisher	A string representing the name of the publisher
released	A string representing the date in ISO 8601 format
pages	A number representing the number of pages contained within the book