与 JavaScript 一起使用

只需使用 EntitySchema 即可获得具有清除身份映射的新副本。

¥Since MikroORM 3.2, we can use EntitySchema helper to define own entities without decorators, which works also for Vanilla JavaScript.

在 本节 中阅读有关 EntitySchema 的更多信息。

¥Read more about EntitySchema in this section.

以下是此类实体的示例：

¥Here is an example of such entity:

./entities/Author.js

import { Collection, EntitySchema } from '@mikro-orm/core';
import { Book } from './Book.js';
import { BaseEntity } from './BaseEntity.js';

/**

 * @property {number} id

 * @property {Date} createdAt

 * @property {Date} updatedAt

 * @property {string} name

 * @property {string} email

 * @property {number} age

 * @property {boolean} termsAccepted

 * @property {string[]} identities

 * @property {Date} born

 * @property {Collection<Book>} books

 * @property {Book} favouriteBook

 * @property {number} version

 * @property {string} versionAsString
 */
export class Author extends BaseEntity {

  /**

   * @param {string} name

   * @param {string} email
   */
  constructor(name, email) {
    super();
    this.name = name;
    this.email = email;
    this.books = new Collection(this);
    this.createdAt = new Date();
    this.updatedAt = new Date();
    this.termsAccepted = false;
  }

}

export const schema = new EntitySchema({
  class: Author,
  properties: {
    name: { type: 'string' },
    email: { type: 'string', unique: true },
    age: { type: 'number', nullable: true },
    termsAccepted: { type: 'boolean', default: 0, onCreate: () => false },
    identities: { type: 'string[]', nullable: true },
    born: { type: DateType, nullable: true, length: 3 },
    books: { kind: '1:m', entity: () => 'Book', mappedBy: book => book.author },
    favouriteBook: { kind: 'm:1', type: 'Book' },
    version: { type: 'number', persist: false },
  },
});

不要忘记提供 name 和 path 模式参数以及 entity 和 schema 导出。

¥Do not forget to provide name and path schema parameters as well as entity and schema exports.

引用 kind 参数可以是以下之一（其中 SCALAR 是默认值）：

¥Reference kind parameter can be one of (where SCALAR is the default one):

enum ReferenceKind {
  SCALAR = 'scalar',
  ONE_TO_ONE = '1:1',
  MANY_TO_ONE = 'm:1',
  ONE_TO_MANY = '1:m',
  MANY_TO_MANY = 'm:n',
  EMBEDDED = 'embedded',
}

我们可以像往常一样注册我们的实体：

¥We can register our entities as usual:

const orm = await MikroORM.init({
  entities: [Author, Book, BookTag, BaseEntity],
  dbName: 'my-db-name',
});

我们还可以将 EntitySchema 实例传递给 entities 数组。

¥We can also pass the EntitySchema instance to the entities array.

有关纯 JavaScript 实体定义的更多示例，请查看 Express JavaScript 示例。

¥For more examples of plain JavaScript entity definitions take a look Express JavaScript example.