Many to many relationships

[chathuraa]

Hi Simon,

What is the best way to have many to many relationships? at which point does this cache the doc, on insert?

Thanks,
Chat.

[Herteby]

It might be a bit unclear, but "one" and "inverse" are actually many-to-one (with "one", a parent can only have one child, but many parents could have the same child).

"many" and "many-inverse" are many-to-many. Which one to use depends on if you're storing the _ids on the children or the parents.

There are 5 update hooks: parent.insert, parent.update, child.insert, child.update and child.remove

Basically you should always be able to rely on the caches being updated no matter what you do. If they're not, that should be considered a bug.

Caches are updated immediately and synchronously, so you could do:

Posts.insert({_id:'post1', authorId:'user1'})
Posts.findOne('post1').author //will contain the cached user

There is one exception: the cacheField() update is always deferred, to work properly with "recursive caching"

[chathuraa]

Hey Simon,

I'm struggling to get this working, I might be missing something. This is my code. What am I doing wrong?

import Allocations from '../api/allocations';

const Appointments = new Mongo.Collection('appointments');
// Appointments.attachSchema(AppointmentsFullSchema);
if (Meteor.isServer) {
  Appointments._ensureIndex({
    workorderNo: 1,
    extWorkorderRef1: 1,
    extWorkorderRef2: 1,
  });
  Meteor.publish('appointments', () => Appointments.find({}));
  Appointments.cache({
    type: 'one',
    collection: Allocations,
    fields: ['_id', 'date', 'from', 'to'],
    referenceField: 'appointmentId',
    cacheField: '_scheduledFor',
    bypassSchema: true,
  });
}

[Herteby]

Since the referenceField is "appointmentId", I'm guessing this is actually an "inverse" relationship?

[chathuraa]

Yeah, that worked. Thanks.

…

On Fri, Sep 8, 2017 at 11:57 PM, Simon Herteby ***@***.***> wrote: Since the referenceField is "appointmentId", I'm guessing this is actually an "inverse" relationship? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#8 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ACTfwVaVGxv2SgE_mfyCALcpcB6fBH5Dks5sgUfTgaJpZM4POBrb> .

-- Thanks, *Chathura Ambegoda.*