How to handle flexible data models

MongoDB Atlas App Services & Realm Realm
1

I have an app where a few documents will not have a fixed schema. That is, say I have a project document and in my project a user can add sections to the document. So, maybe:

  • Project, just one root node
  • Project / Servers, here I may have several server objects I need to add
  • Project / Servers / OS, here I might have dozens of different types of OS’s that I will track all with different fields of different types

Is this possible to do with Realm? I know it supports the more simple case where I know exactly the structure of an object ahead of time. But, what if I don’t know the structure ahead of time?

My app is pretty large and will have hundreds of these types sub-documents (nested objects say within a Project document) where the schema / structure will be highly dynamic. In fact, a high degree of my data will have a structure that changes frequently.

I’m hoping I can still use Realm to just sync/upload/download whatever I hand it. But, looking through the docs I’m not so sure.

Thanks!

2

There are many ways you can choose to model a structure like that. Usually the easiest way will be to add a dictionary to the objects so it can have extra unstructured values. You could do something like this (in Swift, but you could do this in any of the SDK’s):

class Project: Object {
    @Persisted(primaryKey: true) var _id: ObjectId
    @Persisted var name = ""
    @Persisted var servers: MutableSet<Servers>
}

class Servers: Object {
    @Persisted(primaryKey: true) var _id: ObjectId
    @Persisted var name = ""
    @Persisted var os: OS?
    @Persisted var properties: Map<String, AnyRealmValue>
}

class OS: Object {
    @Persisted(primaryKey: true) var _id: ObjectId
    @Persisted var name = ""
    @Persisted var properties: Map<String, AnyRealmValue>
}
1 Like
3

Ok that makes sense. Glad to hear and so far I’m just basically in love with Realm for my app so I’m glad this use case can work.

Alright, off I go…