Delete everything in a MongoDB database

user_66226 0
Viewed 340852

I'm doing development on MongoDB. For totally non-evil purposes, I sometimes want to blow away everything in a database—that is, to delete every single collection, and whatever else might be lying around, and start from scratch. Is there a single line of code that will let me do this? Bonus points for giving both a MongoDB console method and a MongoDB Ruby driver method.

mongodb
17 Answers
db.getCollectionNames().forEach(c=>db[c].drop())
user_10069440

in case you'd need to drop everything at once: (drop all databases at once)

mongo --quiet --eval 'db.getMongo().getDBNames().forEach(function(i){db.getSiblingDB(i).dropDatabase()})'
user_8052840

I prefer

db.your_collection.remove({})

over

db.your_collection.drop()

If your collection was a special collection i.e a capped collection or a collection with one field marked as unique, dropping will clear the collection itself and when collection is again created it will be an ordinary collection. You will have to define the properties again. So use remove() to clear the documents without removing the collection and affecting the behavior of the collection.

user_57740040

In MongoDB 3.2 and newer, Mongo().getDBNames() in the mongo shell will output a list of database names in the server:

> Mongo().getDBNames()
[ "local", "test", "test2", "test3" ]

> show dbs
local  0.000GB
test   0.000GB
test2  0.000GB
test3  0.000GB

A forEach() loop over the array could then call dropDatabase() to drop all the listed databases. Optionally you can opt to skip some important databases that you don't want to drop. For example:

Mongo().getDBNames().forEach(function(x) {
  // Loop through all database names
  if (['admin', 'config', 'local'].indexOf(x) < 0) {
    // Drop if database is not admin, config, or local
    Mongo().getDB(x).dropDatabase();
  }
})

Example run:

> show dbs
admin   0.000GB
config  0.000GB
local   0.000GB
test    0.000GB
test2   0.000GB
test3   0.000GB

> Mongo().getDBNames().forEach(function(x) {
...   if (['admin', 'config', 'local'].indexOf(x) < 0) {
...     Mongo().getDB(x).dropDatabase();
...   }
... })

> show dbs
admin   0.000GB
config  0.000GB
local   0.000GB
user_56197240
Related