db.getSiblingDB()¶

Definition定义¶

db.getSiblingDB(<database>)¶

Parameter参数	Type类型	Description描述
database	string	The name of a MongoDB database.

Returns:	A database object.

Used to return another database without modifying the db variable in the shell environment.

Example示例¶

You can use db.getSiblingDB() as an alternative to the use <database> helper. This is particularly useful when writing scripts using the mongo shell where the use helper is not available. Consider the following sequence of operations:

db = db.getSiblingDB('users')
db.active.count()

This operation sets the db object to point to the database named users, and then returns a count of the collection named active. 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.count()
users.active.findOne()

records.requests.count()
records.requests.findOne()

This operation creates two db objects referring to different databases (i.e. users and records) and then returns a count and an example document from one collection in that database (i.e. active and requests respectively.)