Mongodb Set 4

$and: [ {key1: value1}, {key2:value2} ] ✘ $AND: [ {key1: value1}, {key2:value2} ] ✘ #and: [ {key1: value1}, {key2:value2} ] ✘ use AND: [ {key1: value1}, {key2:value2} ] ✔

The first 3 bytes represent seconds since unix epoch. ✘ The next 4 bytes represent machine identifier. ✘ The next 3 bytes are for process id. ✘ The last 3 bytes represent random counter value. ✔

newObjectId = ObjectId() ✘ newObject = ObjectId() ✘ newObjectId == ObjectId() ✘ ObjectId()=newObjectId ✔

ObjectId==str ✘ changeObjectId.str ✘ newObjectId.str ✘ newObjectId=ObjectId.str ✔

db.collection.field (distinct, query) ✘ db.collection.distinct(field, query) ✘ db.collection.distinct.field. query ✘ db. field, query ✔

rewrite() ✘ replace() ✘ erase() ✘ update() ✔

It will automatically close after client has exhausted all results in the cursor. ✘ It will remain open after client has exhausted all results in the cursor. ✘ Both of these ✘ None of these ✔

Mongo shell will decide ✘ Mongod will decide ✘ Individual language drivers will decide ✘ Mongo will decide ✔

Aggregate ✘ Where ✘ Group ✘ None of these ✔

findOne() returns only the first one ✘ findOne() returns cursors to the collection documents ✘ findOne() gives the actual first document retrieved from a collection ✘ find.limit(1) is not the same query as findOne() ✔