mikro-orm-relationships.ts

// OrgMembership.ts

@ManyToOne(() => User, { ref: true, onDelete: 'cascade' })
user: Ref<User>;

// User.ts

@OneToMany(() => OrgMembership, 'user')   // 'user' is actually type-safe. You can't just enter any string
orgMemberships = new Collection<OrgMembership>(this);

// Notice there is no @Field() on either end of the relationship. If you try
// this, the GraphQL response will contain an object with the correct ID, but no
// other fields. 
//
// So we will use @ResolveField() to load related entities for GraphQL API
// calls.