Definition
Compatibility
This method is available in deployments hosted in the following environments:
MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud
Note
This command is supported in all MongoDB Atlas clusters. For information on Atlas support for all commands, see Unsupported Commands.
MongoDB Enterprise: The subscription-based, self-managed version of MongoDB
MongoDB Community: The source-available, free-to-use, and self-managed version of MongoDB
Example
You can use db.getSiblingDB() as an alternative to the use
<database> helper. This is particularly useful when writing scripts
using mongosh where the use helper is not
available.
Consider a MongoDB instance with two databases, users and
records. The active collection is a part of the users
database. The requests collection is a part of the records
database.
Specify a Database
This operation sets the db object to point to the database named
users, and then returns a document count for the active collection.
db = db.getSiblingDB('users') db.active.countDocuments()
Use Multiple Databases
You can create multiple db objects, that refer to different
databases, as in the following sequence of operations:
users = db.getSiblingDB('users') records = db.getSiblingDB('records') users.active.countDocuments() users.active.findOne() records.requests.countDocuments() records.requests.findOne()
This operation creates two db objects. Each db object refers to
a different database, users or records.
For each database, the query returns:
a
document count, and
from a collection in that database.