我是流星的新手。我已经建立了发布/订阅的概念。反应性地执行聚合时,我遇到以下错误。

客户代码:

import { Template } from 'meteor/templating';
import { ReactiveVar } from 'meteor/reactive-var';
import './main.html';

Template.header.helpers({
    'tasks': function () {
        console.log("tasks helper called : ");

        Meteor.subscribe('reportTotals', function() {
            console.log(clientReport.find().fetch());
        });

        return ['1', '2'];
    },
});


服务器代码

import { Meteor } from 'meteor/meteor';
import {ReactiveAggregate} from 'meteor/jcbernack:reactive-aggregate';

Meteor.startup(() => {
    console.log("Server Started");
  // code to run on server at startup
  var MONGO_URL = "mongodb://127.0.0.1:27017/test";
});

Meteor.publish("reportTotals", function() {
// Remember, ReactiveAggregate doesn't return anything
this.autorun(function () {
ReactiveAggregate(this, atm_data, [{
    // assuming our Reports collection have the fields: hours, books
    $group: {
        '_id': null,
        'bottles_used': {
        // In this case, we're running summation.
            $sum: '$BOTTLE_USED'
            // $sum: 1
        }
    }
}, {
    $project: {
        // an id can be added here, but when omitted,
        // it is created automatically on the fly for you
        bottles_used: '$bottles_used'
    } // Send the aggregation to the 'clientReport' collection available for client use
}], { clientCollection: "clientReport" });
    });
});


刷新DDP缓冲写入时发生异常:错误:期望找到要更改的文档
    在Object.update(http://localhost:3000/packages/mongo.js?hash=ed0b13aca2f180af120dd0cfdba64ac79e2a624f:246:29
...
提前致谢。

最佳答案

您没有客户端集合。另外,您需要订阅才能调用此帮助器。

尝试这个

import { Template } from 'meteor/templating';
import { ReactiveVar } from 'meteor/reactive-var';
import './main.html';

var clientReport = new Mongo.Collection('clientReport');

Meteor.subscribe("reportTotals");

Template.header.helpers({
    'tasks': function () {
        console.log("tasks helper called : ");
        console.log(clientReport.find().fetch());
    },
});


您也不需要管道,也不需要在服务器代码上自动运行,请尝试以下操作:

AtmData = new Mongo.Collection('atmdata');

Meteor.startup(() => {
  // code to run on server at startup
/*     AtmData.insert({
        bottles_used: 123,
    }); */

});



Meteor.publish("reportTotals", function() {
// Remember, ReactiveAggregate doesn't return anything

    ReactiveAggregate(this, AtmData, [{
        // assuming our Reports collection have the fields: hours, books
        $group: {
            '_id': null,
            'bottles_used': {
            // In this case, we're running summation.
                $sum: '$bottles_used'
                // $sum: 1
            }
        }
        }], { clientCollection: "clientReport" });
});

关于javascript - 如何在 meteor 中 react 聚合mongodb,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/39776409/

10-09 20:20
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