remove all collections mongodb code example

Example 1: mongo remove all dbs

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

Example 2: mongodb delete all documents

# To remove all documents in a collection, call the remove method with an empty query
# document {}. The following operation deletes all documents from the bios collection:

db.bios.remove( { } )

Example 3: delete collection mongodb

db.collection.drop()

Example 4: delete an item from db collection mongodb

db.collection.remove(
   <query>,
   {
     justOne: <boolean>,
     writeConcern: <document>
   }
)