add to nested json in mongoDB

Question

For an instance I have a json document in mongodb

{
a:{b:c}
}

Now what am I suppost to do if I want to add to a nested json which will make it look like:

{
a:{b:c, d:e}
}

I have read the documentation of update. It has documented about $inc, $rename, $set & $unset. But I want it to add with existing elements of a. just like $addToSet do with an array.

Answer 1

You can use the $set operator:

collection.update({'a.b': 'c' }, {$set: {'a.d': 'e'}} )