Specify which database to use in mongodb .js script
mongo <name of db> --eval "db.runCommand( <js in here> );"
Or if you dont have a specific runCommand script, you can just do:
mongo <name of db> --eval "<js in here>;"
If you are using a return value:
mongo <name of db> --eval "db.eval('return fnName()')"
For a file
mongo <name of db> some_instructions.js
You can use the db.getSiblingDB()
method, as mentioned here and in the MongoDB documentation.
// Equivalent for "use <db>" command in mongo shell
db = db.getSiblingDB('foo')
This is particularly useful when writing scripts using the mongo shell where the use
helper is not available. Or when you cannot refer to the DB on the connection string.