How to drop or delete a collection in MongoDB?

So either of these are valid ways to do it:

mongo <dbname> --eval 'db.<collection>.drop()'
#     ^^^^^^^^            ^^^^^^^^^^^^

db.<collection>.drop()
#  ^^^^^^^^^^^^

For example, for a collection mycollection in a database mydb you would say:

mongo mydb --eval 'db.mycollection.drop()'

db.mycollection.drop()

This is the way I fully tested it, creating a database mydb with a collection hello.

  • Create db mydb:

    > use mydb
    switched to db mydb
    
  • Create a collection mycollection:

    > db.createCollection("mycollection")
    { "ok" : 1 }
    
  • Show all the collections there:

    > db.getCollectionNames()
    [ "mycollection", "system.indexes" ]
    
  • Insert some dummy data:

    > db.mycollection.insert({'a':'b'})
    WriteResult({ "nInserted" : 1 })
    
  • Make sure it was inserted:

    > db.mycollection.find()
    { "_id" : ObjectId("55849b22317df91febf39fa9"), "a" : "b" }
    
  • Delete the collection and make sure it is not present any more:

    > db.mycollection.drop()
    true
    > db.getCollectionNames()
    [ "system.indexes" ]
    

This also works (I am not repeating the previous commands, since it is just about recreating the database and the collection):

$ mongo mydb --eval 'db.mycollection.drop()'
MongoDB shell version: 2.6.10
connecting to: mydb
true
$

We can also use,

> db["collection-name"].drop()

Its useful when you have some special characters in collection name like '-'


To drop a collection users of database mydb:

> use mydb
> db.users.drop()