I just want to run a .js script against a particular mongodb database, but can't seem to get the correct syntax.
echo "print(db.address.find().limit(1));" > test.js
mongo test.js
How do I select the database that this will be executed on, I've tried various combinations of use foo with no success.
> show dbs
admin (empty)
local (empty)
foo 0.203125GB
bar 0.203125GB
I would like to use foo in this case.
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
$ (and some other characters) as special characters! So you should either use single quotes ('<js in here>') or escape $ and other special characters with a backslash: mongo mydbname --eval "JSON.stringify( db.mycollectionname.find({count: {\$lte:1} }).limit(2).toArray() )" It may be worth changing the quotes in your answer to single quotes, Chris?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.
