node.jsgraphqlprismaprisma-graphqlprisma2

Remove all items in table with Prisma2 and Jest


I would like to know how can I remove all items in table with Prisma2 and Jest ?

I read the CRUD documentation and I try with this :

user.test.js

....
import { PrismaClient } from "@prisma/client"

beforeEach(async () => {
    const prisma = new PrismaClient()
    await prisma.user.deleteMany({})
})
...

But I have an error :

Invalid `prisma.user.deleteMany()` invocation:
The change you are trying to make would violate the required relation 'PostToUser' between the `Post` and `User` models.

My Database

CREATE TABLE User (
  id INTEGER PRIMARY KEY AUTO_INCREMENT NOT NULL,
  name VARCHAR(255),
  email VARCHAR(255) UNIQUE NOT NULL,
  password VARCHAR(255) NOT NULL
);

CREATE TABLE Post (
  id INTEGER PRIMARY KEY AUTO_INCREMENT NOT NULL,
  title VARCHAR(255) NOT NULL,
  createdAt TIMESTAMP NOT NULL DEFAULT now(),
  content TEXT,
  published BOOLEAN NOT NULL DEFAULT false,
  fk_user_id INTEGER NOT NULL,
  CONSTRAINT `fk_user_id` FOREIGN KEY (fk_user_id) REFERENCES User(id) ON DELETE CASCADE
);

schema.prisma

model Post {
  content    String?
  createdAt  DateTime @default(now())
  fk_user_id Int
  id         Int      @default(autoincrement()) @id
  published  Boolean  @default(false)
  title      String
  author     User     @relation(fields: [fk_user_id], references: [id])

  @@index([fk_user_id], name: "fk_user_id")
}

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

Solution

  • You are violating the foreign key constraint between Post and User. You can not remove a User before deleting its Posts

    beforeEach(async () => {
        const prisma = new PrismaClient()
        await prisma.post.deleteMany({where: {...}}) //delete posts first
        await prisma.user.deleteMany({})
    })
    

    Or set CASCADE deletion on the foreign key, this way when you delete a User its posts will be automatically deleted