Hello, how do I implement something like this: When a user send a new message from the client, I need to count them at the end of the month and give user how much messages he sent during this month. I understand that I’ll need to aggregate and count them by date range, but the problem is that how do I trigger such an event. Any advice on how to implement something like that?

If this is something you will notify the user about (without them asking for it) it sounds like a CRON job with some way to push the info to the user. If this is a native app, most of them come with some way of scheduling certain tasks. Anyways you can specify filters to the primsa queries. Does that answer your question? I'm not 100% I got what you were asking for.

@Jenkins yeah I guess, I forgot that I can run it at the first day of each month instead of at the end of each month. But I guess my problem will be that for example: I have a lot of users and each of them need to receive information on how much messages he’s sent on previous month. Basically I can just do a queue something like

bull

for example and add a task to run that aggregation.

You can define any queries you'd like and just run that, yeah. Queries between your GQL server and the Prisma backend does not need to match 1:1 🙂 For example, you could define:

query {
  sentMessagesLastMonth(userId: ID!) {
    count
  }
}

or something similar. And behind that you'd be querying the db with something like:

const resolver = (parent, args, ctx) => {
  return ctx.db.query.messagesConnection({where: {
    userId: args.userId
  }, filter: {
    // your filters go here
  }}, `{ count }`);
};

this is just me pulling syntax out of my ass, but that's the general gist.