seldom used but powerful aggregation operators

Siva talks about the MongoDB Aggregation operators and how to use them to get the maximum benefits. Good code samples help us understand complex use-cases!

rails learning

Most programmers who use MongoDB may have heard about its aggregation framework but only a few have used it to its full potential. Recently, in one of our projects, we got a complex requirement where the user needed to generate a report of sales done for any day, month or year. Using just MongoDB queries would have been very slow compared to the aggregation framework. So I decided to take up the challenge and learn the aggregation operators and make my code awesome! Here are the operators that helped me:

1. $and

$and is one of the MongoDB aggregation conditional operators where you can specify multiple conditions. Any document which satisfies all these conditions would get forwarded to next stage in the pipeline which is nothing but $group stage. Here is an example

The above example returns the $agreement_amount if it is today’s booking.

2. $add and $subtract

Similar to…

View original post 200 more words

Advertisements

About Gautam Rege

Rubyist, Entrepreneur and co-founder of Josh-Software - one of the leading Ruby development shops in India.
This entry was posted in General. Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s