meteor 将对象拉出数组并放置在新字段中
示例
db.posts.find().forEach(function(doc){
if(doc.commenters){
var firstCommenter = db.users.findOne({'_id': doc.commenters[0]._id });
db.clients.update({_id: doc._id}, {$set:{'firstPost': firstCommenter }}, false, true);
var firstCommenter = db.users.findOne({'_id': doc.commenters[doc.commenters.length - 1]._id });
db.clients.update({_id: doc._id}, {$set:{'lastPost':object._id}}, false, true);
}
});