我正在开发一个聊天系统,我尝试使用mongoDB/mongoose的changeStream。
我只想在当前用户是收件人的情况下获取文档,但它不起作用。到目前为止,我遇到过两个案例。一个永远不会触发,另一个会返回所有文档,即使当前用户不是收件人。
区别在于管道是否在数组中。
你知道什么是正确的语法吗?
<小时/>我读了最近两天在google上找到的所有前10页的文章,但没有一篇包含如何过滤。据我了解,聚合管道仅用于操作结果,但不可能排除不通过条件的文档。
<小时/>这是我所做的:
const pipeline = [{
$match: {
"userId": this.recipient.id,
"recipientId": this.user.id
}
}]
const stream = MessageModel.watch(pipeline )
stream.on('change', (data: any) => {
console.log(`messages changed`);
this.socketIo.sockets.in(this.socket.id).emit(`protected/message/subscribe/${this.msg.msgId}`, data.fullDocument);
});
最佳答案
这可能有用
const { ReplSet } = require('mongodb-topology-manager');
const mongoose = require('mongoose');
run().catch(error => console.error(error));
async function run() {
console.log(new Date(), 'start');
const bind_ip = 'localhost';
// Starts a 3-node replica set on ports 31000, 31001, 31002, replica set
// name is "rs0".
const replSet = new ReplSet('mongod', [
{ options: { port: 31000, dbpath: `${__dirname}/data/db/31000`, bind_ip } },
{ options: { port: 31001, dbpath: `${__dirname}/data/db/31001`, bind_ip } },
{ options: { port: 31002, dbpath: `${__dirname}/data/db/31002`, bind_ip } }
], { replSet: 'rs0' });
// Initialize the replica set
await replSet.purge();
await replSet.start();
console.log(new Date(), 'Replica set started...');
// Connect to the replica set
const uri = 'mongodb://localhost:31000,localhost:31001,localhost:31002/' +
'test?replicaSet=rs0';
await mongoose.connect(uri);
// To work around "MongoError: cannot open $changeStream for non-existent
// database: test" for this example
await mongoose.connection.createCollection('people');
const Person = mongoose.model('Person', new mongoose.Schema({ name: String }));
// Create a change stream. The 'change' event gets emitted when there's a
// change in the database
Person.watch().
on('change', data => console.log(new Date(), data));
// Insert a doc, will trigger the change stream handler above
console.log(new Date(), 'Inserting doc');
await Person.create({ name: 'Axl Rose' });
console.log(new Date(), 'Inserted doc');
}
关于node.js - 如何过滤 Mongoose changeStream,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/57637479/