Querying key-value map in mongo [duplicate]

Question

I have documents stored in mongo database following this schema:

{
   map:{
         key1:value,
         banana:value2 
         ....
        }

}

How can I query objects based on keys in this map ?

e.g I want to get all the documents which map contains key that equals banana.

Answer 1

Maps are accessed the same way as normal nested values. This means that you can use the $exists operator to check if the key exists.

db.collection.find( { "map.banana" : { $exists : true } } );