MongoDB: how to change field type from NumberLong to String?

Question

MongoDB

Collection for example:

db.longs.insert({ "_id" : NumberLong("724756511264022954") });
db.longs.insert({ "_id" : 12477933649175871000 });

You need to turn all _id into strings. Google sent me to stackoverflow , where they offered this option:

db.longs.find().forEach( function (x) {   
  x._id = new String(x._id);
  db.longs.save(x);
});

Then it
db.longs.find()
outputs this thread:

{ "_id" : NumberLong("724756511264022954") }
{ "_id" : 12477933649175871000 }
{ "_id" : 12477933649115871000 }
{ "_id" : { "0" : "N", "1" : "u", "2" : "m", "3" : "b", "4" : "e", "5" : "r", "6" : "L", "7" : "o", "8" : "n", "9" : "g", "10" : "(", "11" : "\"", "12" : "7", "13" : "2", "14" : "4", "15" : "7", "16" : "5", "17" : "6", "18" : "5", "19" : "1", "20" : "1", "21" : "2", "22" : "6", "23" : "4", "24" : "0", "25" : "2", "26" : "2", "27" : "9", "28" : "5", "29" : "4", "30" : "\"", "31" : ")" } }
{ "_id" : { "0" : "1", "1" : "2", "2" : "4", "3" : "7", "4" : "7", "5" : "9", "6" : "3", "7" : "3", "8" : "6", "9" : "4", "10" : "9", "11" : "1", "12" : "7", "13" : "5", "14" : "8", "15" : "7", "16" : "1", "17" : "0", "18" : "0", "19" : "0" } }
{ "_id" : { "0" : "1", "1" : "2", "2" : "4", "3" : "7", "4" : "7", "5" : "9", "6" : "3", "7" : "3", "8" : "6", "9" : "4", "10" : "9", "11" : "1", "12" : "1", "13" : "5", "14" : "8", "15" : "7", "16" : "1", "17" : "0", "18" : "0", "19" : "0" } }

Tried also:

db.longs.find().forEach( function (x) {   
  a = x._id.valueOf().toString();
  x._id = new String(a.valueOf());
  db.longs.save(x);
});

But, almost the same result turned out (except that the letters and special characters from _id disappeared)

Answer 1

db.longs.find().forEach( function (x) {
  var oldId = x._id;
  var updateFlag = false;
  if (typeof x._id == "number") {
    updateFlag = true;
    x._id = x._id+"";
  } else if(x._id instanceof NumberLong) {
    updateFlag = true;
    x._id = x._id.toNumber().toString();
  }
  if (updateFlag) {
    db.longs.save(x);
    db.longs.remove({"_id":oldId});
  }
});

Answer 2

All template engines are the same, choose the one whose syntax you like.

Answer 3

Do you need to explain why template engines are needed?
What's the point of using templates?
The difference between handlebars and smarty is that one is for javascript and the other is for php. You will not be able to use handlebars in a php project and vice versa.

Answer 4

https://github.com/janl/mustache.js

Answer 5

They have slightly different purposes, HandleBars - used on the client side, Smart - on the server side. So their use can be combined.

Answer 6

I would recommend jade.