author-optional-props.ts

@Entity()
export class Author {

  // only `name` will be considered as required for `em.create()`
  [OptionalProps]?: 'createdAt' | 'updatedAt';

  @PrimaryKey()
  id!: number;

  @Property({ defaultRaw: 'current_timestamp()' })
  createdAt!: Date;

  @Property({ onUpdate: () => new Date(), length: 3, defaultRaw: 'current_timestamp(3)' })
  updatedAt!: Date;

  @Property()
  name!: string;

}