node.js - Mongoose and findAndModify -

i use node.js mongoose plugin. need try select single document query like:

{   _id: '52261c53daa9d6b74e00000c',   someadditionalflag: 156 } 

and if , if succeeds change flag value. moreover, find , modify operation needs atomic. please, how achieve using mongoose?

you don't need use findandmodify don't need original document. can use update this:

mymodel.update({   _id: '52261c53daa9d6b74e00000c',   someadditionalflag: 156 }, {   $set: {someadditionalflag: newvalue } }, function(err, numaffected) { ... }); 

in callback, numaffected 1 if change made, otherwise 0.