entities.ts

import { Exclude, Expose } from "class-transformer";
import {
  Column,
  Entity,
  ManyToMany,
  PrimaryGeneratedColumn,
} from "typeorm";

@Entity()
export class Project {
  @Expose()
  @PrimaryGeneratedColumn()
  id: number;

  @Expose()
  @Column({ length: 50 })
  name: string;

  // Relations
  @Expose()
  @ManyToMany(() => User, (user) => user.projects, { cascade: true })
  @JoinTable()
  users: User[];
}

@Entity()
export class User {
  @Expose()
  @PrimaryGeneratedColumn()
  id: number;

  @Expose()
  @Column({ type: "varchar", length: 255, nullable: false, unique: true })
  email: string;

  // Password and stuff
  @Exclude()
  @Column({ type: "varchar", length: 100, nullable: false })
  password: string;

  @Expose()
  @Column({ nullable: true, length: 50 })
  firstName?: string;

  @Expose()
  @Column({ nullable: true, length: 50 })
  lastName?: string;

  @Expose()
  @ManyToMany(() => Project, (project) => project.users)
  projects: Project[];
}

Error

QueryFailedError: Cannot delete or update a parent row: a foreign key constraint fails (`db`.`project_users_user`, CONSTRAINT `FK_f8300efd87679e1e21532be9808` FOREIGN KEY (`userId`) REFERENCES `user` (`id`))

      at new QueryFailedError (../../../src/error/QueryFailedError.ts:11:9)
      at Query.onResult (../../../src/driver/mysql/MysqlQueryRunner.ts:193:37)
      at Query.execute (../../../node_modules/mysql2/lib/commands/command.js:30:14)
      at PoolConnection.handlePacket (../../../node_modules/mysql2/lib/connection.js:425:32)
      at PacketParser.onPacket (../../../node_modules/mysql2/lib/connection.js:75:12)
      at PacketParser.executeStart (../../../node_modules/mysql2/lib/packet_parser.js:75:16)
      at Socket.<anonymous> (../../../node_modules/mysql2/lib/connection.js:82:25)

test.ts

describe("test", () => {
  const userIds = [1, 2, 3]; // some user ids
  afterEach(async () => {
  // here's the problem
    await connection
      .createQueryBuilder()
      .delete()
      .from(User)
      .whereInIds(userIds)
      .execute();
  });
});