Delete - MongoDB

Delete All Documents Matching

db.students.deleteMany({ "FirstName": "Anna" })

Delete the First Document that Matches

db.students.deleteOne({ "FirstName": "Anna" })

https://docs.mongodb.com/manual/reference/method/db.collection.deleteOne/#db.collection.deleteOne

Delete All

db.students.deleteMany({})

{} is Wildcard for all

delete Database

use databaseName 
db.dropDatabase()