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?
03 Answers
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 mydbCreate 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
$To drop a collection users of database mydb:
> use mydb
> db.users.drop()--eval "db.getCollection('collection').drop()"
