Question

I can’t figure out how to remove documents that I created while testing my app. From within the mongo shell I get this:

> db.carshare.remove();
> show dbs
carshare    0.203125GB
crushFlow   0.203125GB
local   (empty)
test    (empty)
> db.carshare.remove({});
> show dbs
carshare    0.203125GB
crushFlow   0.203125GB
local   (empty)
test    (empty)

I’m a beginner and must be missing something very obvious, help?

Answer 1

MongoDB has a hierarchy structure that is DB -> collection -> documents.

So, are you trying to remove a DB, a collection, or a document?

Assuming a DB ‘foo’, with a collection ‘test’, with two documents:

> db.test.find();
{ "_id" : ObjectId("4ef54ed6c143a725c52d7ff6"), "name" : "mongo" }
{ "_id" : ObjectId("4ef54eeec143a725c52d7ff7"), "name" : "bob" }

to remove a document:

> db.test.remove({'name':'bob'});
> db.test.find();
{ "_id" : ObjectId("4ef54ed6c143a725c52d7ff6"), "name" : "mongo" }

to remove a collection:

> db.test.drop();
true
> show collections;
system.indexes

to remove a DB:

db.dropDatabase();
{ “dropped” : “foo”, “ok” : 1 }

The Mongo documentation is very good:

http://www.mongodb.org/display/DOCS/Overview+-+The+MongoDB+Interactive+Shell#Overview-TheMongoDBInteractiveShell-Deleting

http://www.mongodb.org/display/DOCS/dbshell+Reference