http://www.linuxask.com/questions/drop-a-database-in-mongodb
Drop a database in MongoDB
Answer:
Assuming you are going to drop the `test` database in MongoDB, follow the steps below to drop (delete) it.
> use test
switched to db test
> db.dropDatabase()
{ "dropped" : "test.$cmd", "ok" : 1 }
原文：http://www.cnblogs.com/seasonzone/p/4227389.html