本机节点mongodb驱动程序在由Mongo-C创建时返回正确的文档，但数字数组为空

Question

请查看底部的编辑。这似乎是Mongo-C和/或本机节点mongodb的问题，而不是Mongoose的问题。

我有一个存储在MongoDB中的地震数据的实时集合。一个称为data的键是一个样本的int数组。当我通过Mongoose查询这个集合时，一切看起来都很好，但数据键返回为空数组，而is应该返回为长度为nsamp（样本数）的Number数组。

我已经将Mongoose模式定义为：

var waveformSchema = new Schema({
    key:        String,
    nsamp:      Number,
    starttime:  Number,
    endtime:    Number,
    samprate:   Number, 
    datatype:   String,
    data:       [Number]
 });

通过mongo 查询以下记录

db.cwaves.find({"_id" : ObjectId("5733bedeadb31b2b8a0fef2e")})

它返回

{ "_id" : ObjectId("5733bedeadb31b2b8a0fef2e"), 
"key" : "BROK.HNZ.UW.--", "nsamp" : 172, 
"starttime" : 1463008988.38, "endtime" : 1463008989.2350001,
"samprate" : 200, "datatype" : "i4", 
"data" : [ 1385, 1384, 1385, 1384, 1381, 1386, 1390, 1381, 1385,
           1387, 1382, 1387, 1384, 1381, 1385, 1386, 1384, 1382,
           1383, 1384, 1386, 1384, 1381, 1385, 1386, 1384, 1386,
           1386, 1385, 1385, 1387, 1382, 1383, 1386, 1381, 1382,
           1384, 1382, 1383, 1386, 1386, 1382, 1383, 1386, 1384,
           1385, 1385, 1384, 1387, 1387, 1383, 1383, 1388, 1385,
           1384, 1387, 1382, 1383, 1385, 1384, 1385, 1384, 1383,
           1385, 1384, 1383, 1387, 1382, 1386, 1387, 1381, 1386,
           1386, 1390, 1386, 1383, 1388, 1381, 1384, 1389, 1385,
           1384, 1386, 1387, 1384, 1382, 1384, 1382, 1378, 1387,
           1390, 1383, 1385, 1383, 1381, 1384, 1385, 1387, 1380,
           1379, 1387, 1383, 1384, 1384, 1384, 1385, 1382, 1389,
           1389, 1381, 1385, 1388, 1387, 1386, 1383, 1386, 1383,
           1382, 1385, 1382, 1384, 1386, 1383, 1382, 1385, 1386,
           1386, 1387, 1385, 1382, 1380, 1383, 1387, 1378, 1382,
           1388, 1383, 1385, 1387, 1385, 1386, 1388, 1386, 1384,
           1382, 1382, 1385, 1385, 1384, 1378, 1384, 1387, 1383,
           1383, 1382, 1384, 1384, 1388, 1386, 1380, 1386, 1388,
           1386, 1383, 1384, 1384, 1383, 1387, 1385, 1384, 1386,
           1382 ] 
      }

但如果我在Mongoose中进行同样的查询，那么数据数组是空的：

var mongoose = require('mongoose')
    , assert = require('assert')
    , app = require('express')()
    , http = require('http').Server(app)
    , io = require('socket.io')(http);
//schema stuff and things
var Schema = mongoose.Schema;
var waveformSchema = new Schema({
  key:        String,
  nsamp:      Number,
  starttime:  Number,
  endtime:    Number,
  samprate:   Number, 
  datatype:   String,
  data:       [Number]
});

var Cwave = mongoose.model('Cwave', waveformSchema);
//get configs
var Conf = require("./config.js"); //config file
var conf = new Conf();
//Connect to Mongo
var url = "mongodb://" + conf.mongo.user + ":" + conf.mongo.passwd + "@" 
  + conf.mongo.host + ":" + conf.mongo.port + "/" + conf.mongo.dbname 
  + "?authMechanism=" + conf.mongo.authMech + "&authSource=" + conf.mongo.authSource;
mongoose.connect(url);
var db = mongoose.connection;
db.on('error', console.error.bind(console, 'connection error:'));
db.once('open', function() {
   Cwave.find({"_id" : "5733bedeadb31b2b8a0fef2e"}, function(err, cwaves){
     if (err) return console.error(err);
     console.log(cwaves);
    });
});

我得到以下控制台输出：

listening on port: 8888
[ { data: [],
  datatype: 'i4',
  samprate: 200,
  endtime: 1463008989.2350001,
  starttime: 1463008988.38,
  nsamp: 172,
  key: 'BROK.HNZ.UW.--',
  _id: 5733bedeadb31b2b8a0fef2e } ]

我对模式的定义正确吗？

编辑1:将脚本更改为：

  Cwave.find({"_id":"5733bedeadb31b2b8a0fef2e"}).lean().exec(
        function(err, cwaves){ if (err) return console.error(err);
        console.log(cwaves); })

收益率：

[ { _id: 5733bedeadb31b2b8a0fef2e,
    key: 'BROK.HNZ.UW.--',
    nsamp: 172,
    starttime: 1463008988.38,
   endtime: 1463008989.2350001,
   samprate: 200,
   datatype: 'i4',
   data: [ data: 1382 ] } ]

编辑2：在尝试以上操作后，它可能是本机mongodb驱动程序。我将脚本更改为：

var  MongoClient  = require('mongodb').MongoClient
    , assert = require('assert')
    , app = require('express')()
    , http = require('http').Server(app)
    , io = require('socket.io')(http);
//get configs
var Conf = require("./config.js"); //config file
var conf = new Conf();
//Connect to Mongo
var url = "mongodb://" + conf.mongo.user + ":" + conf.mongo.passwd + "@" 
      + conf.mongo.host + ":" + conf.mongo.port + "/" + conf.mongo.dbname 
      + "?authMechanism=" + conf.mongo.authMech + "&authSource=" + conf.mongo.authSource;

MongoClient.connect(url, function(err, db) {
    if(err) throw err;
    var collection = db.collection('cwaves');
    collection.find({starttime: 1463008988.38, key: "BROK.HNZ.UW.--"}).toArray(function(err, results) {
        console.log(results);
        db.close();
      });
});

得到了与编辑1相同的结果。

[ { _id: 5733bedeadb31b2b8a0fef2e,
    key: 'BROK.HNZ.UW.--',
    nsamp: 172,
    starttime: 1463008988.38,
   endtime: 1463008989.2350001,
   samprate: 200,
   datatype: 'i4',
   data: [ data: 1382 ] } ]

编辑3：MongoDb集合是通过使用Mongo-C的C程序填充的。我创建了三个类似的文档：1）通过mongo-c例程（原始），2）节点mongodb和3）mongo控制台。当我查找时，它们在mongo控制台中看起来很相似（除了id和密钥名称），所以我觉得没有必要添加输出，除非有人真的想要它

MongoClient.connect(url, function(err, db) {
    if(err) throw err;
    var collection = db.collection('cwaves');
    collection.find().toArray(function(err, results) {
        // console.log(result);
        for(var i=0; i< results.length; i++){
          console.log("key: " + results[i].key + " type: " + Object.prototype.toString.call(results[i].data) + " length: " + results[i].data.length);
        }
        db.close();
      });
});

哪个收益率：

key: BROK.HNZ.UW.-- type: [object Array] length: 0
key: mongo_console type: [object Array] length: 172
key: node-mongodb type: [object Array] length: 172

我使用mongogem创建了一个ruby脚本，并且能够读取所有三个数组。

Answer 1

这是我使用libbson构建数组时的一个错误。我的C代码中的阵列构建部分是：

bson_append_int32（m_data，"data"，-1，long_data[i]）；

第二个参数是键，我认为应该是数组键"data"。但它应该是作为字符串的索引。

http://api.mongodb.com/libbson/current/bson_append_int32.html

因此阵列构建部分变成：

   char index[4];

   bson_append_array_begin (m_doc, "data", -1, m_data);
    for ( i = 0; i < trh->nsamp; i++ ){
      snprintf(index, 4, "%d", i);
      if ( (strcmp (trh->datatype, "s2")==0) || (strcmp (trh->datatype, "i2")==0) ){
        bson_append_int32 (m_data, index, -1, short_data[i]);
       }else{
         bson_append_int32 (m_data, index, -1, long_data[i]);
       }
      }
    bson_append_array_end (m_doc, m_data);                             

我不明白为什么第一个版本使用mongo控制台或ruby库。