mongodb convert find with sort order to findAndModify

Question

I have successfully got the one of the users with the lowest referrals using the node native driver

users.find().sort({referrals:1}).limit(1).toArray(function(error,result){
    console.log(error||result);
    });

^ this works fine

v this and other variations I have tried don't

When I want to make the function better by findAndModify I fail over and over (this is the closest I Think I have got from the docs)

users.findAndModify({},{referrals:1},{$inc:{referrals:1}},{}).toArray(function(error,result){                                                          
    console.log(error||result);
    });

I want to get one of the users with the lowest referrals and ++1 his referrals when I find him

You can do it in two steps - 1) Aggregating to get the lowest value 2)Updating the lowest value result — Avi, Dec 25 '15 at 21:53
the whole point of findAndModify is that it gets done in 1 step! — Ben Muircroft, Dec 25 '15 at 22:14

score 1 · Answer 1 · edited Jun 20 '20 at 09:12

1

Try to do it with this query:

db.users.findAndModify({
    sort: {referrals:1}, 
    update: {$inc: {referrals:1}}, 
    new: true
}, callback)

Here you can see all possible parameters for findAndModify.

edited Jun 20 '20 at 09:12

Community

1
1

answered Dec 26 '15 at 00:34

Volodymyr Synytskyi

3,885
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score 0 · Accepted Answer · edited May 23 '17 at 12:30

For those who might also be using the node native driver:

Based on this answer https://stackoverflow.com/a/24326067/990434

The .findAndModify() method in the node native driver implementation is different from the mongo shell implementation. The main difference being you do not name the "key" sections for the actions.

So in this case the code would be:

db.users.findAndModify(
     {}//query
    ,{referrals:1}//sort
    ,{$inc:{referrals:1}}//update
    ,{new:true}
    ,function(error,result){});

mongodb convert find with sort order to findAndModify

2 Answers2