Many-to-Many Relationships the Redwood Way™️

[thedavid]

Ok, @crabasa, take a look at this:
https://github.com/thedavidprice/crabasa-schema

Note: to be clear about @rob’s comment above re: Prisma complaining about CategoriesOnPosts → I could run yarn rw db save and yarn rw db up just fine. It was yarn rw g post that failed if the model CategoriesOnPosts was present.

I used a local setup (so packages from RWJS ‘master’ branch). Started with our template from repo ‘create-redwood-app’. Then ‘yarn linked’ built packages. In the App for local dev I had to yarn add -W Prisma packages @prisma/cli, @prisma/client, @prisma/sdk

I was able to scaffold both Post and Category models, but only after I removed CategoriesOnPost.

Note: I git committed each migration and generator step separately

@rob mentioned he thought this was already handled automatically by Prisma for relations. And, when I looked at the dev.db tables, here’s what I saw:

Doesn’t look exactly like the table you were trying to build. But something is happening behind the scenes here.

Here’s the schema.prisma I used:

datasource DS {
  provider = "sqlite"
  url      = env("DATABASE_URL")
}

generator client {
  provider      = "prisma-client-js"
  binaryTargets = env("BINARY_TARGET")
}

model Post {
  id         Int        @default(autoincrement()) @id
  title      String
  categories Category[] @relation(references: [id])
}

model Category {
  id    Int    @default(autoincrement()) @id
  name  String
  posts Post[] @relation(references: [id])
}