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I have a really complicated issue that i think i can solve by writing a mongo shell script but i can't even manage to make a simple connection. I have a local mongo database which is requires a username/password that i normally access like this:

mongo admin -u <username> -p

at which point I enter the password and hooray! i have a shell. but that won't work for my issue. As a test, I created a file called test.js and all it has in it is this:

var conn = new Mongo()

db = conn.getDB("test");
db.cust.find();

I then run the script from the command line like so:

mongo test.js

at which point i get this:

MongoDB shell version: 2.4.10
connecting to: test

Why am i getting no results?

Dallas Caley
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1 Answers1

24

I finally made this work. This is how i ended up doing it:

First I made a file called test.js with the following in it:

db = connect("localhost:27017/admin");

db.auth('username','password');

db = db.getSiblingDB('test');

var cursor = db.cust.find();

while (cursor.hasNext()) {
   printjson(cursor.next());
}

I then ran this command from the command line:

mongo test.js

I also want to point out a few things that i learned while trying to do this to any other developer who is having issues.

1) if you add a new database, and your are running mongo with authentication you either need to log into the authentication database first and then switch to the desired database (as my example shows) or you need to add a user/password to the desired database (as i probably should have done in the first place)

2) When running a javascript file via mongo, don't expect to use the same "javascript" functions that you are used to. I just learned a hard lesson that not all javascript is the same. for example, you can not use Console.log() in a javascript file that is run via mongo because console.log is not actually core javascript but rather a function specific to browser and node implementations.

Dallas Caley
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  • Found this answer really helpful, thanks. Also ended up getting additional help here: https://docs.mongodb.com/manual/tutorial/write-scripts-for-the-mongo-shell/ – Ivan Maeder May 23 '18 at 20:11
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    I also found this really helpful. I ended up revising the first three lines a bit to what seems IMHO a bit cleaner: `var mongo = new Mongo('localhost:27017'); mongo.getDB("admin").auth('username', 'password'); var db = mongo.getDB('test');` – Collin Krawll Oct 11 '18 at 19:26