{"id":2506,"date":"2015-02-24T13:15:15","date_gmt":"2015-02-24T11:15:15","guid":{"rendered":"http:\/\/www.webcodegeeks.com\/?p=2506"},"modified":"2015-02-24T13:05:39","modified_gmt":"2015-02-24T11:05:39","slug":"introduction-backbone-query-api","status":"publish","type":"post","link":"https:\/\/www.webcodegeeks.com\/javascript\/backbone-js\/introduction-backbone-query-api\/","title":{"rendered":"Introduction to the Backbone Query API"},"content":{"rendered":"

As a relatively \u201cnew\u201d user of Backbone.js, I looked at different JSON querying tools that existed. At the time I was still struggling with using JSON as the data source and wrapping my head around the process for querying the data set that was contained in a large string. Coming from a Java and strong PL\/SQL background in Oracle, I wanted to find something akin to the PL\/SQL language I was used to. So I set out on a quest to find something that would whet my appetite.<\/p>\n

Some folks like to just simply use Underscore with the _.each or _.findwhere, or another of the other API choices for narrowing the result set down. I, on the other hand, wanted a more precise querying tool that could give me the \u201clikes,\u201d \u201cgreater\/less than,\u201d and case-insensitive type searches.<\/p>\n

I thought that there had to be something out there that does these types of things already. So I searched and found things like JsLinq, SQLike, and so on. Some were okay, but as I was also new to the Backbone scene, I wanted it to translate well to Backbone.<\/p>\n

I found backbone_query<\/a> much to my liking. The API was built for Backbone specifically and had a lot of the items I was looking for.<\/p>\n

Getting Started<\/h2>\n

You can use the standalone file, Jam install, or NPM install into Node.js for use. From there it is pretty simple. All you need to do is create Backbone.QueryCollection instead of the existing Backbone.Collection. This allows the new collection, which extends Backbone.Collection, to be queried with the API.<\/p>\n

Query API<\/h3>\n

Here is a basic example:<\/p>\n

MyCollection.query({\r\n    new: true,\r\n    amount: {$gt:10}\r\n});<\/pre>\n
You can see here that the code is pretty similar to that of an Underscore _.findWhere({new: true}) search. So, syntactically it is very similar. Now let me show a little more advanced query:<\/p>\n
MyCollection.query(\r\n    {tags: { $any: ['cheese', 'bread', 'cat litter']}},\r\n    {sortBy: 'name', order: 'desc'}\r\n);<\/pre>\n
The query above searches the \u201ctag\u201d field and tries to find any of the given values. It also sorts the result by name desc. You can see that this type of querying and ordering can come in handy. It can allow you to only return the results of the query, but sort in many different ways.<\/p>\n
Here is an example of the $equal property. It doesn\u2019t have to be explicitly used, but can be:<\/p>\n
MyCollection.query({ title:'Test' });\r\nMyCollection.query({ title: {$equal:'Test'} }); \/\/ Same as above<\/pre>\n
The query returns all matches where title = \u2018Test\u2019.<\/p>\n
In addition there are many different operators to use for narrowing down your searches. Some of which are:<\/p>\n