Prisma Cascade Delete

Prisma (v2) is one of the hottest ORM's right now (you can see some of the reasion I think so here). It still has some important holes, though. Cascade delete is one of the most proeminent ones, and most of the "automatic" workarounds have some issue.

This package exposes a cascadeDelete function that uses the information available at the prisma models to perform cascade deletes on one-to-many and many-to-many (with a relation table) relations. The cascade goes as deep as the relation goes (see example below).

Installation

npm install prisma-cascade-delete

Usage

import { cascadeDelete } from "prisma-cascade-delete";

cascadeDelete(prisma, modelName, where);
// prisma is the prisma-client instance from your app
// modelName must be the same as used in the prisma schema (e.g. "User")
// where is an object accepted by prisma queries as a *where* statement

Example

model User {
  id    Int     @id @default(autoincrement())
  email String  @unique
  name  String?
  posts Post[]
}

model Post {
  id        Int      @id @default(autoincrement())
  title     String
  content   String?
  published Boolean  @default(false)
  viewCount Int      @default(0)
  author    User    @relation(fields: [authorId], references: [id])
  authorId  Int
}

model Tag {
  id        Int      @id @default(autoincrement())
  name      String
}

model TagsInPost {
    id       Int     @id @default(autoincrement())
    post     Post    @relation(fields: [postId], references: [id])
    postId   Int
    tag      Tag     @relation(fields: [tagId], references: [id])
    tagId    Int

}

In the schema above, we would expect that if we delete a User, all its Posts and all the Tags associated to this posts would be deleted as well. However, there is no way to set this up.

That's where cascadeDelete comes in;

import { cascadeDelete } from "prisma-cascade-delete";
import { PrismaClient } from "@prisma/client";

const prisma = new PrismaClient();

cascadeDelete(prisma, "User", { id: 1 });

This function will generate

const userDelete = prisma.user.delete({ where: { id: 1 } });
const postsDelete = prisma.post.deleteMany({ where: { userId: 1 } });
const postTagDelete = prisma.tagsInPost.deleteMany({
  where: { OR: [{ postId: 1 }, { postId: 2 }] },
}); 
// Imagining that the user posted posts 1 and 2

prisma.$transaction([postTageDelete,postsDelete,userDelete])