Commands in mongodb 2.6

As with any other database MongoDB is a NoSQL database in which informaiton is stored, retrieved, manipulated. This is accomplished using CRUD commands – Create, Read, Update and delete. In addition to this MongoDB offers advanced features in form of MongoDB commands
So, what is a mongoDB command?
to implement functionality that falls outside scope of CRUD mongodb makes use if commands. They assist with many different operations of mongoDB collections
Some popular MongoDB commands include :
1) getlasterror()
2) db.runcommand({“drop”:”collectionname”); – This is a good example of drop command
MongoDB supports many such commands
How do I ge tlist of commands from MongoDB?
To get to know list of commands supported by particular version of MongoDB run :
db.listcommands()

TypeError: Property ‘findone’ of object dbname.collection is not a function

This error occurs while using the findone() function in mongodb. findone() function is used to return first value in a database collection
db.collection.findOne()- correct format
The reason for above error being – db.collection.findone()
Make sure mongodb is javascript oriented and is case sensitive