mongodb commands I find useful, especially when dealing with embedded documents.

mongocommands.txt

//To remove a field from each document. Whenever I introduce a field by mistake 
db.example.update({}, {$unset: {words:1}} , {multi: true});

//To search in array of objects in mongodb
db.collection.find( { field1: { $elemMatch: { one: 1 } } } );

//To update array of objects in mongodb console
db.roles.update({"userId" : ObjectId("58a191b8d02dde3638a5a4ee"), "children.requestStatus" : 'Rejected'},{$set : {"children.$.requestStatus" : "Authorized"}})