I’m trying to model something in Ecto where records share a few common fields, but depending on a type, they have completely different additional fields. Roughly: there’s an items table with the common stuff (type, same_field, etc.) and then separate tables for each type (items_a, items_b) these …

Sure thing! I’ll clean it up and push it a bit later and let you know. Note I made a mistake in the API I showed which I’ve edited. I just forgot the belongs_tos so the one macro is doesn’t do anything too magical. It’s has a lot in common with how test works which is outlined in the official gu…

I recently read a good blog post on this: [image] Subtypes and status-dependent data: pure relational approach Using constant columns to solve a common problem of encoding status-dependent information (or subtypes, more generally). This is about the plain db…

I really like this, thanks for sharing. It’s quite clever and a pretty clean solution.

As promised here is the repo . I’m a bit embarrassed by the preload_one as I was in the middle of working on it (this was made with 0 vibes) but I keep hopping around on projects and I need to stop doing that so here ya go! I think the approach linked by LK is a much more interesting way of doing t…

This is a non-answer but something I learned to do early on in a project is not even worry about it and just have all the columns on the one table and then document the schema which fields belong to which subtype and then have separate changesets for creating the different subtypes. This is usually…

This is the strategy my library was trying to solve. We did just this at my last job but it ballooned very quickly. EDIT: By “solve” I mean make easier, but same idea: it’s when you put all the sub types right on the parent table and only allow one of them to be present.

Whats easy in SQL are hard in Ecto. Thats why I’m building GitHub - elixir-dbvisor/sql: SQL provides state-of-the-art, high-performance SQL integration for Elixir, built to handle extreme concurrency with unmatched expressiveness and ergonomic query composition. Write safe, composable, parameterize…

Oh ya, I keep meaning to check this out. It looks really nice I just haven’t played with it yet as there are a bunch of things I wanna do (and someone recently starting to use AI a bit has made that worse). I’ve also been heavy into an Ash project and I’m ass-u-me’ing it wouldn’t make much sense t…

Then there’s no time to refactor the database schema. I always encourage people to not half-ass the database design. Do it properly from the get go. It’s like in sports. If you lack the fundamentals, it’s very hard to compensate afterwards.

It depends Ash can’t do everything and you will eventually have to write SQL, I never worked on a project that never had to do that at somepoint. I’m looking forward to tackle migrations next as thats when are going to take a fresh look at what a Ecto.Schema or Ash.Resource is in the world of a rela…

How do you model different ‘types’ with totally different fields in Ecto?

Questions & Help Questions

zachdaniel April 15, 2026, 3:08am 17

Curious to know what kind of thing you have in mind here.