how to join two tables in mongodb

Question

how to join two tables in mongodb.

For example, table 1 : users table 2 : examples

Here users table having username and examples table also having username,

Answer 1

Unfortunately there is no merging/joining operation directly in MongoDB. Anyway, you can use the map-and-reduce functionality in order to combine the data appropriately.

Depending on your actual problem, the following links might be of help:

MongoDB: Combine data from multiple collections into one..how?

Merging two collections in MongoDB

http://www.pal-blog.de/entwicklung/mongodb/mapreduce-multiple-mongodb-collections-into-one.html

https://groups.google.com/forum/#!topic/mongodb-user/OQUH_wxYyRg

https://groups.google.com/forum/#!topic/mongodb-user/qxa7ZBTk7sQ