Question

我一直在尝试返回一个数组（childz），它接受链式promises中循环mongoose查询的结果但是当我在consolelog结果时它仍然是一个空数组。我之前确实嵌套过，但我认为链接它要好得多，但我仍然不知道如何正确地返回这些异步结果。

SCHEMA：

var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var PK = mongoose.Types.ObjectId;
var RK = mongoose.Schema.ObjectId;

var CommentSchema = Schema({
    body: {type: String},
    chapterId: {type: RK, ref: 'Chapter'},
    by: {type: RK, ref: 'User'},
    children: [{
        type: RK,
        ref: 'Comment'

     }]
}, {timestamps: true});

CODE：

commentController.reply = function(req,res){

  var commentList;
  var newComment = new Comment(req.body);
  newComment.save();
  //console.log(newComment);
  var commid = req.body.comid;
  var dataa;
  //console.log(req.body.comid);
  //console.log(req.body.body);
  //console.log(req.body.xxchid);
  //console.log(req.body.by);


  Comment.findByIdAndUpdate(
    commid,
    {$push: {children: newComment}},
    {new: true}, 
     function(err, post){
      if(err){
        console.log(err);
      } else{
         //console.log(post+"haha")


      }

     }


    )


    var childz = [];

    Comment.find({chapterId: req.body.xxchid}).then(function(data){

      //console.log(data+"data");
      dataa = data;
      //console.log(dataa+"dataa");


        }).then(function(){



        Comment.find({_id: commid}).then(function(onlydata){



                for(var i=0;i<onlydata[0].children.length;i++){



          Comment.find({_id: onlydata[0].children[i]}).then(function(onlydatac){



              childz.push(onlydatac[0].body);
              console.log(childz+"imchildz");//does print this as it should. shows all the elements appropriate



          })



        }


   })


}).then(function(result){

  console.log(result+"result");
  for(var i=0;i<childz.length;i++){         //doesnt print out anything. 
    console.log(childz[i]+"really"+i);
  }
  console.log(childz); //shows an empty array []
  return res.send({commentList: dataa, comidd: commid, childs: childz})

})

}

Answer 1

有两个错误。首先使用accumulate正在使用回调接口，然后你也在调用它。其次，你没有在“父母”承诺中回报承诺。

Comment.findByIdAndUpdate

您还可以使用Comment.findByIdAndUpdate(commid, {$push: {children: newComment}}, {new: true}) .exec() .then(post => { var childz = []; return Comment.find({chapterId: req.body.xxchid}) .exec() .then(function(data){ var dataa = data; // don't know the use of it return Comment.find({_id: commid}) .exec() .then(onlydata => { return Promise.all(onlydata[0].children.map(child => { return Comment.find({_id: child}) .exec() .then((onlydatac) => { childz.push(onlydatac[0].body); }); })); }); .then(() => { return childz; }); }); });使事情更容易理解。

async-await

然后链接mongodb / nodejs没有返回填充数组

1 个答案: