MongoDB update multiple records of array [duplicate]

Answer 1

One solution could be creating a function to be used with a forEach and evaling it (so it runs quickly). Assuming your collection is "article", you could run the following:

var runUpdate = function(){
    db.article.find({"comments.user":"test").forEach( function(article) {
        for(var i in article.comments){
            article.comments[i].avatar = 'new_avatar.jpg';
        }
        db.article.save(article);
    });
};

db.eval(runUpdate);