Mongoose query aggregation

[Aranad]

Is there any way to use the Mongo/Mongoose collection aggregation-pipline from feathers-mongoose?

[jamesjnadeau]

I don't think there is, as it strays too far from the "unified query system"(or whatever it's called, please correct me),

You could extend/override the find/_find functions to customize this to your will though.

[corymsmith]

@Aranad I've created custom services that use aggregation underneath. Or if you need an aggregation in addition to other data from a service you could add an after hook that does the aggregation as well.

[Aranad]

@corymsmith that sounds awesome... could you point me in the right direction to read up on and implement that, thanks! :-)

[subodhpareek18]

maybe try putting the params in params.mongoose

[corymsmith]

@Aranad Theres some info here on creating a custom service, unfortunately my custom service is proprietary so I can't share it: https://docs.feathersjs.com/api/services.html

[Aranad]

I figured out a way to do it from the before.find hook. hook.service.Model is the mongoose model object that has aggregate() available, so I made a convention for passing aggregate data in find() which the hook can detect and divert to the aggregate method :-)

[corymsmith]

Perfect!

[daffl]

Glad it worked! Closing this one then.

[stalinb87]

@Aranad how exactly do you accomplish this, do you have some example?

[Aranad]

@stalinb87 yes I documented how I did it here: https://www.organicdesign.co.nz/Our_SPA#Database_schemas_and_querying, a similar method could also be done with the hook creating the complex query server-side instead of the whole aggregation query structure being passed from client to server.

[MacgyverMartins]

You can override context.params.query at before.find hook whit the mongoose query

[priyabagus]

Example aggregate for users

await app.service('users').Model.aggregate( [ { <stage1> }, { <stage2> } ... ] )