In MongoDB, you can use the Object.bsonSize() method to return the size of a document in bytes.
methods
MongoDB Date() Method
In MongoDB, the Date() method returns a date either as a string or as a Date object.
- When you call it as
Date(), it returns the current date as a string in themongoshell. - When you call it as
new Date(), it returns the current date as a Date object.
You can also provide a specific date as an argument to new Date(), so that it uses that date.
MongoDB countDocuments()
In MongoDB the db.collection.countDocuments() method returns the count of documents that match the query for a collection or view.
The collection part is the name of the collection or view to perform the count operation on.
MongoDB distinct()
In MongoDB, the db.collection.distinct() method finds the distinct values for a specified field across a single collection or view and returns the results in an array.
Distinct values are those with redundant duplicates removed. Distinct values are unique values. For example, if you have 2 or 3 documents with the same value, the distinct command will return just one value.
db.collection.distinct() is a shell wrapper method for the distinct command.
MongoDB cursor.count()
In MongoDB the cursor.count() method counts the number of documents referenced by a cursor..
Note that it doesn’t actually perform the query. It simply counts and returns the number of results that would be returned by the query.
The cursor.count() method is a wrapper for the count command.
MongoDB db.collection.count()
In MongoDB the db.collection.count() method returns the count of documents that would match a find() query for the collection or view.
The collection part is the name of the collection or view to perform the count operation on.
Note that it doesn’t actually perform a find() operation. It simply counts and returns the number of results that match a query.
MongoDB count Command
In MongoDB the count aggregation command counts the number of documents in a collection or a view.
It returns a document that contains the count as well as the command status.
MongoDB find()
In MongoDB the db.collection.find() method selects documents in a collection or view and returns a cursor to the selected documents..
The collection part is the name of the collection or view to search.
You can use it to return all documents, just some, or just one document. You can also specify which fields should be returned.
MongoDB findOne()
In MongoDB the db.collection.findOne() method returns one document that satisfies the specified query criteria on the collection or view.
The collection part is the name of the collection or view to search.