mongodb-query

问题 I have an object with the following form : { "_id": ObjectId("4fa43f4d1cf26a6a8952adf1"), "userId": "1", "facebookId": "1234", "groups": [{ "groupName": "testGroup", "members": [{ "memberFirstName": "userFirstName", "memberLastName": "userLastName", "memberDetails": { "userId": "1", "faceBookId": "1234" } }] }] } It's a collection that holds for each user - its groups, with each group containing the group members... So the "groups" key is an array (or list), and so is the "members" key. (each

问题 I am using the below query on my MongoDB collection which is taking more than an hour to complete. db.collection.find({language:"hi"}).sort({_id:-1}).skip(5000).limit(1) I am trying to to get the results in a batch of 5000 to process in either ascending or descending order for documents with "hi" as a value in language field. So i am using this query in which i am skipping the processed documents every time by incrementing the "skip" value. The document count in this collection is just above

问题 I have a collection and each document in that collection has an array field countries . I want to select all documents which include any of below countries: China, USA, Australia And the output should show the number of above countries each document has. I use below aggregate command: db.movies.aggregate([ { $match: { countries: { $in: ["USA", 'China', 'Australia'] } } }, { $project: { countries: {$size: '$countries'} } } ]); it doesn't work as expected. It shows the number of all countries

问题 How do I define the following MongoDB aggregate query in mongoose: db.contacts.aggregate([{$group: { "_id": { code: "$Code", name: "$Name" } } }]) The objective of the query is to pull a list of distinct codes and names. My current model code is: '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

问题 I have a collection like { "_id" : ObjectId("5738cb363bb56eb8f76c2ba8"), "records" : [ { "Name" : "Joe", "Salary" : 70000, "Department" : "IT" } ] }, { "_id" : ObjectId("5738cb363bb56eb8f76c2ba9"), "records" : [ { "Name" : "Henry", "Salary" : 80000, "Department" : "Sales" }, { "Name" : "Jake", "Salary" : 40000, "Department" : "Sales" } ] }, { "_id" : ObjectId("5738cb363bb56eb8f76c2baa"), "records" : [ { "Name" : "Sam", "Salary" : 90000, "Department" : "IT" }, { "Name" : "Tom", "Salary" :

问题 I have such this type of structure of my database. I want to find number of documents my "JAN" array contains. I am trying to do in different way but nothing works. That would be great if someone helps. { "_id" : ObjectId("5cd8609db20663a19e2c362c"), "2017" : { "JAN" : [ { "SYMBOL" : "20MICRONS", "SERIES" : "EQ", "OPEN" : "33.4", "HIGH" : "34.3", "LOW" : "33", }, { "SYMBOL" : "3IINFOTECH", "SERIES" : "EQ", "OPEN" : "5.8", "HIGH" : "5.8", "LOW" : "5.55", }, { "SYMBOL" : "3MINDIA", "SERIES" :

问题 Suppose we had something like the following document, but we wanted to return only the fields that had numeric information: { "_id" : ObjectId("52fac254f40ff600c10e56d4"), "name" : "Mikey", "list" : [ 1, 2, 3, 4, 5 ], "people" : [ "Fred", "Barney", "Wilma", "Betty" ], "status" : false, "created" : ISODate("2014-02-12T00:37:40.534Z"), "views" : 5 } Now I know that we can query for fields that match a certain type by use of the $type operator. But I'm yet to stumble upon a way to $project this

问题 I have document like this { "id": "1", "myarray": [ { "_id": "4", "name": "d", "order": 4 }, { "_id": "1", "name": "a", "order": 1 }, { "_id": "2", "name": "b", "order": 2 } ] } i want to see sort data in array by order when get from db i am trying some query like below but it seems not OK and nothing changed db.collection.aggregate([{$unwind: "$myarray"},{$project: {orders:"$myarray.order"}},{$group: {_id:"$_id",min:{$min: "$orders"}}},{$sort: {min:1}}]) db.myarray.find({},{$sort:{"myarray

问题 I've got two schemas, one for user and another one for post in the user schema, I've got a property for latestPost which would be an ObjectId of an entry in the post schema when I load up the user object, I want to get the lastestPost as an object that includes the author's username from the user schema where the author is an ObjectId that'd match an _id field in the user schema. the mongoose tutorials seem to use the syntax of User.findOne({ _id: req.user.id}) .populate('latestPost')

问题 I have mongoDB "users" collection in JSON format and I want to return all the data having privacy is true. How can I do it ? { "name" : "Maria Kari", "social" : [ { "facebook" : "www.fb.com/maria.mongodb", "privacy" : true }, { "twitter" : "www.tw.com/mongodb", "privacy" : false } ], "personal" : [ { "cell_no" : "+1-99082198414", "privacy" : true }, { "email" : "maria@mongodb.com", "privacy" : false } ] } Here, I want to return the data having privacy is true. For example, facebook, it has