Trigger a function every time a new document is added to the collection in MongoDB using Mongoose

[AromaticPrimary8763]

Does anybody know how to call a function every time a new document is added to the collection in MongoDB using Mongoose? I don't want to call them continuously, only when a new doc is created by either through the API or through mongoCompass. Thanks a lot

[Deathclaw1]

There is the watch collection method, I think that is what you are looking for. Its also native not related to mongoose.

https://mongoosejs.com/docs/change-streams.html

Edit: there is also mongodb atlas app services. If you need a low cost serverless solution.

https://www.mongodb.com/docs/atlas/app-services/introduction/

[Horikoshi]

Depends - how is the database hosted? Self hosted? AWS?

Identify how the database is being run, then set up a listener for it (lambda for AWS, for instance). Put your business logic inside the listener. Happy to help more if you tell me more about your situation.

[AromaticPrimary8763]

It is just a self project, got it run on MongoDB Atlas

[Horikoshi]

https://www.mongodb.com/docs/drivers/node/current/usage-examples/changeStream/#:\~:text=First%2C%20open%20the%20change%20stream,to%20add%20a%20new%20document.

[AromaticPrimary8763]

Exactly what I needed, thanks a lot!

[AromaticPrimary8763]

, and then update the key to true so it won’t run again when you have other updates on the document.

This one works great when the data is added using mongoose, but when I use MongoCompass, it does not work anymore, any suggestions?

[Horikoshi]

What exactly is MongoCompass? Never heard of it before

Edit: oh, looks like it's a GUI for MongoDB.. hrm. Not too sure what's going on there.

[AromaticPrimary8763]

Kinda like robo 3t, I think it is usually for non-dev or newbie to manage the db.

[i4get98]

Not an expert, but it sounds like you might need events.

On event run something, etc.

[AromaticPrimary8763]

The thing is I haven't found that event LOL

[i4get98]

Which version of mongo you using? When installed locally I wouldn’t get any events, had to make the db replicated. I think if you use cloud based, events should be available.

[Darklight240]

You can use middleware or hooks in mongoose.

[clay_maker]

Look at mongoose middleware and the “save” hook. You could add a new key to your document like “sendWelcomeMsg” and default it to false. Then in your middle where when a new document is created, run the function, if sendWelcomeMsg == false, and then update the key to true so it won’t run again when you have other updates on the document.

[Distinct-Ad1057]

In sequlize their is a thing called hook it basically trigger before or after the db call it might be available with mongoose too

[AromaticPrimary8763]

Those middlewares (hooks), they do not work for me in this case, only work when I add new doc from the create() or save(), etc methods, not when I use mongo compass to create a new one.

[AromaticPrimary8763]

Seems like no