猫鼬不在循环中保存所有文档 [英] Mongoose not saving all documents in loop

问题描述

所以在Express应用程序中，我有以下用于POST api的代码:

So I have the following code in an Express app for the POST api:

var dashSchema = new mongoose.Schema({
  key: 'string',
  status: 'string',
  assignee: 'string',
  summary: 'string'
});

var dashData = mongoose.model('dashData', dashSchema);


app.post('/api/data', function(req, res) {
  var issues = req.body.issues;

  for (var i=0;i<issues.length;i++) {
    dashData.create({key: issues[i].key, status: issues[i].fields.status.name, assignee: issues[i].fields.assignee, summary: issues[i].fields.summary});
  }

  res.end();
  });

每当我发布5个问题"的数组时，只有前两个会被写入MongoDB.我以为这是因为它可以遍历整个循环所花费的时间，但是我不知道如何使它写入所有数据，然后返回响应.

Whenever I post an array of 5 "issues" only the first two are being written to the MongoDB. I assume this is because that is all it can write in the time it takes to iterate through the loop, but I don't know how to make it write all of the data, and then return the response.

有什么想法吗?

推荐答案

在猫鼬中， .create 返回一个承诺.安装诸如 bluebird 之类的Promise库，以使您可以访问 Promise.all ，您可以执行以下操作:

In Mongoose, .create returns a promise. Install a promise library like bluebird to give you access to Promise.all and you can do this:

var Promise = require('bluebird'); // could also be Q or another A+ library

app.post('/api/data', function(req, res, next) {
  var issues = req.body.issues;

  // map the issues to an array of promises for created dashData docs
  var createdPromises = issues.map(function(issue){
    return dashData.create({key: issue.key, status: issue.fields.status.name, assignee: issue.fields.assignee, summary: issue.fields.summary}); // returns a promise
  });

  Promise.all(createdPromises).then(function(results){
    res.json(results); // only sends when all docs have been created
  }).then(null, next); // error handler - pass to `next`

});

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