Question

My object is like following.

{ "_id" : ObjectId("4ec3ba6fb8af0adbaf2ffc2a"), "list" : { "list1" : "sample", "list2" : "test2" } }

I want to count total record under “list”. Can I do this in shell ?

Answer 1

I don’t think there are any queries on the database side for that. You could use simple map/reduce but in your case probably the easiest way is to just fetch the whole document and then count the items with javascript loop like this:

document = db.yourcoll.findOne(...);
var count = 0;
for (e in document.list) { ++count; }