How to drop or delete a collection in MongoDB?

问题

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?

回答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
$

回答2:

To drop a collection 'users' of database 'mydb':

$ use mydb
$ db.users.drop()

来源：https://stackoverflow.com/questions/30948151/how-to-drop-or-delete-a-collection-in-mongodb

标签

mongodb

collections