How to drop or delete a collection in MongoDB?

Question

What is the best way to drop a collection in MongoDB?

I am using the following:

db.collection.drop()

As described in the manual:

db.collection.drop()

Removes a collection from the database. The method also removes any indexes associated with the dropped collection. The method provides a wrapper around the drop command.

But how can I drop it from the command line?

Solution 1

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
$

Solution 2

To drop a collection users of database mydb:

> use mydb
> db.users.drop()