mongoDB: Aggregation - Is there a equivalent of the $lookup joins for the native node.js driver? -

mongodb: 2.1.3

after reading of aggregation enhancements coming mongodb 3.2 excited "$look" pipeline stage left-outer equi-joins.

unfortunately appears node driver doesn't have operator.(i don't see in native driver docs node , when tried use got error:

update: here code tried

var cursor = db.collection('messagethreads').aggregate([         {"$match": {             _id: new objectid(threadid)}         },          {"$lookup": {             from: "messages",              localfield: "_id",             foreignfield: "threadid",             as: "messageslist"}         }     ]);      cursor.toarray(function(err,messages){         if(err) {             res.status(500).json(error);         }         else if(convo === null){             res.status(400).end();         }         else{             res.status(200).json(messages);         }     }); }); 

example - threadmessage document

{      "_id" : objectid("56b4f52c0e6368c00630aee6"),      name: "messages 1" } 

example - message document

{      "_id" : objectid("56b4f52c0e6368c00630af08"),       "author" : "nick",       "text" : "hello",       "threadid" : objectid("56b4f52c0e6368c00630aee6") }, ... 

intended result

{     "_id" : objectid("56b4f52c0e6368c00630aee6"),      name: "messages 1",     messagelist:[         {          "_id" : objectid("56b4f52c0e6368c00630af08"),           "author" : "nick",           "text" : "hello",           "threadid" : objectid("56b4f52c0e6368c00630aee6")         },         ...     ] } 

" mongoerror: exception: unrecognized pipeline stage name: '$lookup' "

you can read more case joins here!

question: there intended way perform equivalent node.js native driver?

the "mongoerror" exception how driver reports error messages "server", , therefor such error indicates server connected not version suppport $lookup, being 3.2 or greater:

$lookup

new in version 3.2.

performs left outer join unsharded collection in same database filter in documents “joined” collection processing. $lookup stage equality match between field input documents field documents of “joined” collection.

you can obtain server version connecting via serverstatus database command. in full reproducible listing:

var async = require('async'),     mongodb = require('mongodb'),     mongoclient = mongodb.mongoclient,     objectid = mongodb.objectid;  mongoclient.connect("mongodb://localhost/test",function(err,db) {    async.series(     [       function(callback) {         db.command({ "serverstatus": 1 }, function(err,status) {           console.log(status.version);           callback(err);         });       },       function(callback) {         async.each(['threadmessage','message'],function(colname,callback) {           db.collection(colname).remove({},callback);         },callback);       },        function(callback) {         db.collection('threadmessage').insert(           {             "_id" : objectid("56b4f52c0e6368c00630aee6"),             "name": "messages 1"           },           callback         );       },        function(callback) {         db.collection('message').insert(           {             "_id" : objectid("56b4f52c0e6368c00630af08"),             "author" : "nick",             "text" : "hello",             "threadid" : objectid("56b4f52c0e6368c00630aee6")           },           callback         );       },        function(callback) {          var cursor = db.collection('threadmessage').aggregate([           { "$lookup": {             "from": "message",             "localfield": "_id",             "foreignfield": "threadid",             "as": "messageslist"           }}         ]);          cursor.toarray(function(err,result) {           console.log(json.stringify(result,undefined,2));           callback(err);         });       }     ],     function(err) {       if (err) throw err;       db.close();     }   );  }); 

as package.json driver version pinned, show there no driver version issue:

{   "name": "lookup",   "version": "1.0.0",   "description": "",   "main": "index.js",   "scripts": {     "test": "echo \"error: no test specified\" && exit 1"   },   "author": "",   "license": "isc",   "dependencies": {     "async": "^1.5.2",     "mongodb": "2.1.3"   } } 

gives expected output supported server version:

3.2.0 [   {     "_id": "56b4f52c0e6368c00630aee6",     "name": "messages 1",     "messageslist": [       {         "_id": "56b4f52c0e6368c00630af08",         "author": "nick",         "text": "hello",         "threadid": "56b4f52c0e6368c00630aee6"       }     ]   } ] 

so if listing not returning 3.2.x on database connecting to, $lookup pipeline operation not supported here , have resort alternate means, such pulling in "related" information "client side" instead.