Custom Types

[mavilein]

The schema spec contains various statements about custom types aka type definitions. We need clarification on which parts of the spec are confirmed and should be implemented. We need this in order to start work on this epic.

Here are a few questions that come to my mind.

1. Should we implement support for custom complex types from the get go? This would increase the scope significantly. This would require embeds to be implemented before that. E.g.:

embed Point3D {
  X Int
  Y Int
  Z Int
  @@pg.Point
  @@ms.Point
}

2. Do we need to support @raw?
3. In the spec i can see two kinds of ways to define custom types for a field: text String @pg.citext vs. text pg.Citext. I think we lean to the first option but we need confirmation.
4. Some types use named arguments like pg.Varchar(n: 42). Have we settled on this syntax? @pg.varchar(23) was discussed also quite often.

[matthewmueller]

1. Should we implement support for custom complex types from the get go?

I'd be totally find dropping this until after GA

2. Do we need to support @raw?

The @raw is (most likely) generated on demand by the connector when you click on the "Jump to Definition" of @pg.Money. It's mean to serve as the "bottom-layer".

@sorenbs @schickling do we want to allow folks to use this in their schema.prisma files? I'm leaning towards allowing it.

3. In the spec i can see two kinds of ways to define custom types for a field: text String @pg.citext vs. text pg.Citext. I think we lean to the first option but we need confirmation.

I don't think there's consensus on this yet. I'm currently leaning towards: https://github.com/prisma/specs/tree/master/schema#type-definitions-provided-by-connectors

Connectors provide custom types, you can use them in your schema.prisma as:

datasource pg {
  provider = "postgresql"
  url = "..."
}

model User {
  description pg.Varchar(100)
}

We replace @pg.Citext with @raw("citext") at the bottom-layer.

4. Some types use named arguments like pg.Varchar(n: 42). Have we settled on this syntax? @pg.varchar(23) was discussed also quite often.

This should follow the same rules as arguments: https://github.com/prisma/specs/tree/master/schema#attributes

If there is only 1 argument, the key can be omitted, otherwise you need to include the key.

---

Let's try and finalize and I'll update the spec

/cc @sorenbs @schickling