本文介绍了如何在猫鼬中使用聚合的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
如何在猫鼬中定义以下MongoDB聚合查询:
How do I define the following MongoDB aggregate query in mongoose:
db.contacts.aggregate([{$group: { "_id": { code: "$Code", name: "$Name" } } }])查询的目的是提取一系列不同的代码和名称.
The objective of the query is to pull a list of distinct codes and names.
我当前的模型代码是:
'use strict'; var mongoose = require('mongoose'), Schema = mongoose.Schema, ObjectId = Schema.ObjectId; var fields = { Code: { type: String }, Name: { type: String } }; var contactSchema = new Schema(fields); module.exports = mongoose.model('Contacts', contactSchema);路由器看起来像这样:
api.contacts = function (req, res) { Contacts.find({ AgencyTranslation: /^BROADCASTING/ }, function(err, contacts) { if (err) { res.json(500, err); } else { res.json({contacts: contacts}); } });我尝试了各种变体,还查看了以下示例代码: mongoose API文档 ,但似乎无法正常工作.
I tried various variations, also looked up the sample code at: mongoose API docs, but I cannot seem to get it working.
(注意:以上查询在MongoDB控制台中确实有效.)
(Note: the above query does work in the MongoDB console.)
推荐答案尝试一下
Contacts.aggregate({$group: { "_id": { code: "$Code", name: "$Name" } } }, function(err, contacts) { ... });或者,如果需要此AgencyTranslation: /^BROADCASTING/条件,请使用$match
Or, with $match if you need this AgencyTranslation: /^BROADCASTING/ condition
Contacts.aggregate([ { $match : { AgencyTranslation: /^BROADCASTING/ } }, { $group: { "_id": { code: "$Code", name: "$Name" } } } ], function(err, contacts) { // ... });更多推荐
如何在猫鼬中使用聚合
发布评论