I would like to know how to execute a JavaScript file in MongoDB.
This is the simple piece of code present in my JS file:
function loadNames() {
print("name");
}
From the command prompt I tried to execute the file like this
mongo test.js
but it shows the error:
unexpected identifier
Can anyone explain to me where I'm going wrong?
I usually run my test queries like this, and it works with your sample code too.
mongo < test.js
two meothods to achieve this:
1 . use "--eval"
mongo quickstats_db --eval "printjson(db.getCollectionNames())"
2 . execute the js file
mongo quickstats_db print.js
where content of print.js is:
printjson(db.getCollectionNames())
From mongo --help, we got:
$ mongo --help
MongoDB shell version v3.6.2
usage: mongo [options] [db address] [file names (ending in .js)]
db address can be:
foo foo database on local machine
192.168.0.5/foo foo database on 192.168.0.5 machine
192.168.0.5:9999/foo foo database on 192.168.0.5 machine on port 9999
Options:
--shell run the shell after executing files
--nodb don't connect to mongod on startup - no
'db address' arg expected
--norc will not run the ".mongorc.js" file on
start up
--quiet be less chatty
--port arg port to connect to
--host arg server to connect to
--eval arg evaluate javascript
-h [ --help ] show this usage information
... ...
and referred mognodb's tutorial/document, we got this script named as my-mongo-script.js:
'use strict';
// @see https://docs.mongodb.com/manual/tutorial/write-scripts-for-the-mongo-shell/
var MONGODB_URI = "mongodb://127.0.0.1:27020/testdb";
var db = connect(MONGODB_URI);
var collections = db.getCollectionNames();
print(collections.join('\n'));
printjson(collections);
so this cmd mongo --nodb my-mongo-script.js will execute the script.
You can add a "--shell" like mongo --nodb --shell my-mongo-script.js to "run the shell after executing files".
