Bidirectional references in Sanity.io for many-to-many relationships

Are many-to-many relationships possible using references (or anything else)? I was surprised not to find anything about that here, in the docs, or on SO, but surely there’s a way!
I have

items

and

categories

. Each item can have many categories and each category can have many items, which I can set up by adding a reference to each one, except those lists don’t know about each other. What I need is essentially to have one relationship between the two document types that I can set on either one. eg, if I set

item1

to have

categoryA

and then go to

categoryA

, I would expect to see

item1

listed on

categoryA

. Hope that makes sense!

References are bidirectional out of the box, but the studio currently doesn’t show incoming references to a document. You can however create an “input” or preview component that shows all the documents that has referenced it. Here’s a screenshot of one I made for debugging purposes on my own. Will see if I can find the code for it 👍 It wasn't made with the latest version of Sanity, so keep that in mind 😅😇 https://github.com/sanity-io/sanity/tree/victoria/incoming-refs-preview/packages/test-studio/src/previews/incoming-refs
Here’s how I queried for the references:

Thanks for the response ! Can you expand on what bidirectional means for this context? It doesn’t look like it does what I need it to out of the box, so I don’t think it means what I’m hoping for.
To try another example: If I add

itemA

to the list of

items

on

category1

, I also expect

category1

to be added to a list of

categories

on

itemA

. If I then decide I don’t want

itemA

included in that category, I could make this change either by removing the category from

itemA

or by removing the item from the list on

category1

.
Goal: to be able to manage the same relationship between categories and items on either the category or the item. If it’s just a preview component, then it’s not actually part of the list, right?

I’ll take a look at your code to see if that helps though, thanks!

It sounds like you then need a custom input component, and that it’s maybe not as straight forward with references only👍 but by bidirectional I mean that when you reference documents they are “aware of each other”, they just don’t show up in the Studio. But you can list them using the

references

method in GROQ. if you reference a document (A) in document (B), you can do this to list all the references that exist to the document A: , which means that documentB will show up in that list 👍

Okay, thanks!

In your example, does

IntentLink

take you to the edit page of the preview item that it wraps? I might be able to get away with only having a true reference list on one of the types if the other at least lists all with an easy link to get to it.

Also, is

IntentLink

still available? It’s been difficult to follow tutorials without documentation of the

parts

and trying to figure out what’s going on in the source code, and then having the code also in the process of deprecating the parts system.

Yes that’s what the intent link does 👍 I think it’s still around 😊

Hi again 😁 👋 Is it possible to implement the reference list without using structure builder? I may end up needing to get into that later anyway but haven’t needed it yet.

Maybe you can create an input component that’s not actually an input component? Meaning that it only displays a list, but is in the schema

This was super helpful, ended up making a list based on your example but also using Sanity UI and as an “input component” that doesn’t actually take input. Thanks so much and happy new year !

No problem! And that’s awesome, happy to hear you solved it! 😃 Happy new year 🎉