mongodb

问题 I am writing to inform that i had installed mongodb-community some time back using brew (High Sierra) and it was running. Then recently i upgraded and it doesn't seem to wire up. When i am running mongo in terminal, I am getting error: MongoDB shell version v4.4.0 connecting to: mongodb://127.0.0.1:27017/?compressors=disabled&gssapiServiceName=mongodb Error: couldn't connect to server 127.0.0.1:27017, connection attempt failed: SocketException: Error connecting to 127.0.0.1:27017 :: caused by

问题 How to get percentage total of data with group by date in MongoDB ? Link example : https://mongoplayground.net/p/aNND4EPQhcb I have some collection structure like this { "_id" : ObjectId("5ccbb96706d1d47a4b2ced4b"), "date" : "2019-05-03T10:39:53.108Z", "id" : 166, "update_at" : "2019-05-03T10:45:36.208Z", "type" : "image" } { "_id" : ObjectId("5ccbb96706d1d47a4b2ced4c"), "date" : "2019-05-03T10:39:53.133Z", "id" : 166, "update_at" : "2019-05-03T10:45:36.208Z", "type" : "image" } { "_id" :

问题 Can MongoDB allow updating a number field using another number field in same document ? Let say I have a document like below : { "_id" : "1", "a" : 2, "b" : 3 } a and b fields are number fields(decimal,int...) my goal is update field b using field a How can I set b like b = 2*a . Is this possible ? 回答1: Note : On v 3.6 you don't have an option for direct update, You need to first read & process in code, then update. For v >= 4.2 you can do it in one call as .update() will accept aggregation

问题 Can MongoDB allow updating a number field using another number field in same document ? Let say I have a document like below : { "_id" : "1", "a" : 2, "b" : 3 } a and b fields are number fields(decimal,int...) my goal is update field b using field a How can I set b like b = 2*a . Is this possible ? 回答1: Note : On v 3.6 you don't have an option for direct update, You need to first read & process in code, then update. For v >= 4.2 you can do it in one call as .update() will accept aggregation

问题 Can MongoDB allow updating a number field using another number field in same document ? Let say I have a document like below : { "_id" : "1", "a" : 2, "b" : 3 } a and b fields are number fields(decimal,int...) my goal is update field b using field a How can I set b like b = 2*a . Is this possible ? 回答1: Note : On v 3.6 you don't have an option for direct update, You need to first read & process in code, then update. For v >= 4.2 you can do it in one call as .update() will accept aggregation

问题 Let's say a have a simple document: { array: ["a", "b", "c", "d"] } How to modify the second value in aggregation ? With update it is very simple: db.collection.updateOne({}, { $set: { "array.1": "B" } } ) gives: { array: ["a", "B", "c", "d"] } In aggregation framework you can use this one: db.collection.aggregate([ { $set: { "array": { $map: { input: "$array", in: { $cond: { if: { $eq: [{ $indexOfArray: ["$array", "$$this"] }, 1] }, then: "B", else: "$$this" } } } } } } ]) However, this

问题 I'm having a similar problem laid out in this question, but I'm stumbling on a different aspect. I have an array of objects/subdocuments embedded within a document in my mongo database, schema like this.... const projectSchema = new mongoose.Schema({ name: { type: String }, ... stakeholders: [{ stakeholderTitle: { type: String, max: 150, required: [true, 'A stakeholder must have a title.'] }, ... }], what I need to do is update a particular embedded object based on the query, but I still need

问题 I'm using something akin to How to properly reuse connection to Mongodb across NodeJs application and modules to keep my mongoDB Connection open. This requires all the code to go into a MongoDB.connectDB(async (err) => {...} Block. How would I use this when writing Tests with Mocha. Do I have to use a separate Connection for every test? Like this? const MongoDB = require('../src/mongoUtil') // providing access to the mongo database var events = require('../src/events') // containing all my

问题 I'm using something akin to How to properly reuse connection to Mongodb across NodeJs application and modules to keep my mongoDB Connection open. This requires all the code to go into a MongoDB.connectDB(async (err) => {...} Block. How would I use this when writing Tests with Mocha. Do I have to use a separate Connection for every test? Like this? const MongoDB = require('../src/mongoUtil') // providing access to the mongo database var events = require('../src/events') // containing all my

问题 I'm trying to do like search into mongodb with Javascript, but i havent yet figured it out how to do it. Any help is appreciated. I have a search parameter called "search" at request body (req.body.search). I would like find all programs which name contains that search criteria. Ie. "harry" would return " Harry Potter", "Potter Harry ", "How merry Harry Really is?" and other movies which contains harry in its name. exports.programs = function(db, req) { return function(req, res) { var