MongoDB – Count unread messages
I try to count unread messages for a user. On my model, I have a property, LastMessageDate that contains the date on the last created message in the group chat. I have also a Members property (list) that contains the…
Node js – mongodb not responding
Need help, I am trying to learn nodejs from youtube. I have created below but not getting any response from browser. Can you please check below code and advise what I have missed?? if I removed the courseModel.find ... from…
MongoDB — Filter if all objects in array matches another array
Given documents like the one below, I'd like to return _id only if all elements of the input_array matches the list of available objects. For these examples, the first object should match while the second does not because key3 in…
MongoDB – Using Index to get nested IDs is slow
I have a MongoDB collection with 8k+ documents, around 40GB. Inside it, the data follows this format: { _id: ..., _session: { _id: ... }, data: {...} } I need to get all the _session._id for my application. The following…
Mongodb – Query to do indepth search for a regex is not working properly
I'm having one query to do indepth search for a regex in mongoDB. I'm using JS function inside the query like this - db.collection.find( {$where: function() { function deepIterate(obj, value) { var new_value = new RegExp("^"+value, "i"); for (var field…
How to design a system that deals with incrementing registration number in MongoDB
In MongoDB how to create Registration number ? I need auto incrementing value but MongoDB doesn't have auto increment by default (risk in case concurrency failure), so how to do it? Eg. current registration no : 1 now when I…
MongoDB using an array of IDs from one Collection to filter the results based on the IDs from another Collection
Suppose there is a MongoDB Collection CollA. Say CollA has the following three Documents: {"_id": "1", "name": "Bob"}, {"_id": "2", "name": "John"}, {"_id": "3", "name": "Will"} Let's say there is another MongoDB Collection CollB which has the following Document: {…
Mongodb – set all fields in subdocument to false, then set the second one to true in a single query
Suppose I have the following the document structure. [ { "_id": 1, "depots": [ { "_id": 1, "isFavourite": true }, { "_id": 2, "isFavourite": false }, { "_id": 3, "isFavourite": true }, { "_id": 4, "isFavourite": false } ] }…
Mongodb – How to use substring for comparison in mongo db
Below is my aggregation db.customers.aggregate([{ $match: { "CDF.UTILITYTYPE.D1.G1" : "12387835" } }, { $project: { _id:0, "CDF.UTILITYTYPE.D1.G22.NAME":1, "CDF.UTILITYTYPE.D1.G1":1, "CDF.UTILITYTYPE.D5.EVENT": { $filter: { input: "$CDF.UTILITYTYPE.D5.EVENT", as: "item", cond: { $eq: [ "$$item.TIME", "12-04-2018 15:46:02" ] } } } } } ]).pretty();…
MongoDB! query to get data from specific date of different format
I am new in mongoDB, please help me for below question description: I have collection xyz having one of column insertDate having date of dd/mm/YYYY format. I want all records from xyz collection whose insertDate is greater than 28/01/2022. I…