Scaffolds don't handle optional relations with string keys

[Tobbe]

Given this prisma schema

model User {
  id        Int      @id @default(autoincrement())
  email     String   @unique
  name      String?
  addressId String?
  address   Address? @relation(fields: [addressId], references: [id])
}

model Address {
  id           String  @id @default(uuid())
  country      String
  state        String?
  zip          String
  town         String
  street       String
  streetNumber String // Can be 12C for example
  users        User[]
}

If you scaffold user you get this

Trying to create a new user like this you get an error

The front-end says {"errors":[{"message":"Something went wrong."}],"data":null}
The back-end says

api | Invalid `db.user.create()` invocation in
api | /Users/tobbe/dev/redwood/scaffoldnull/api/src/services/users/users.js:14:18
api | 
api |   11 }
api |   12 
api |   13 export const createUser = ({ input }) => {
api | → 14   return db.user.create(
api |   Foreign key constraint failed on the field: `foreign key`

But it should be fine to leave the id out, because the relation is optional

[dthyresson]

Adding a validate to those TextFields works:

        <TextField
          name="purchaserId"
          defaultValue={props.possession?.purchaserId}
          className="rw-input"
          errorClassName="rw-input rw-input-error"
          validation={{
            setValueAs: (val) => {
              if (val === '') {
                return null
              }
            },
          }}
        />

Might be nice to have a setEmptyAsNull: true option on TextField and SelectList

[Tobbe]

Have a PR ready to go, just need #4299 to be merged first