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db.getSiblingDB()![](/docs/v5.3/assets/link.svg)
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Definition![](/docs/v5.3/assets/link.svg)
Example![](/docs/v5.3/assets/link.svg)
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![](/docs/v5.3/assets/link.svg)
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![](/docs/v5.3/assets/link.svg)
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.