Question

我的Mikro-Orm（v3.6.15）模型（连接到Postgresql-pg v8.3.0）中有2个具有一对多关系的实体：

维吾尔玛（父母）

@Entity({ tableName: "Uygulamalar", collection: "Uygulamalar" })
export class Uygulama {
  @PrimaryKey({ fieldName: "Id" })
  id!: number;
  @Property({ fieldName: "Adi" })
  adi!: string;
  @Property({ fieldName: "Kod" })
  kod!: string;
  @Property({ fieldName: "UygulamaSahibi" })
  uygulamaSahibi!: string;
  @Property({ fieldName: "createdAt" })
  createdAt = new Date();
  @Property({ fieldName: "updatedAt", onUpdate: () => new Date() })
  updatedAt = new Date();
  @OneToMany({ entity: () => Modul, mappedBy: "rootUygulama", cascade: [] })
  moduller = new Collection<Modul>(this);
}

模块（儿童）

export class Modul {
  @PrimaryKey({ fieldName: "Id" })
  id!: number;
  @Property({ fieldName: "Adi" })
  adi!: string;
  @Property({ fieldName: "Kod" })
  kod!: string;
  @Property({ fieldName: "createdAt" })
  createdAt = new Date();
  @Property({ fieldName: "updatedAt", onUpdate: () => new Date() })
  updatedAt = new Date();
  @ManyToOne({ entity: () => Uygulama, joinColumn: "UygulamaId", cascade: [],})
  rootUygulama!: Uygulama;
  @OneToMany({ entity: () => Ekran, mappedBy: "rootModul", orphanRemoval: true,})
  ekranlar = new Collection<Ekran>(this);
}

我有一个休息端点（Expressjs）从发布的Http请求主体创建Modul对象：

router.post("/", async (req, res) => {
  const modul = DI.modulRepository.create(req.body);
  await DI.modulRepository.persistAndFlush(modul);
  res.send(modul);
});

当我尝试在下面发布JSON对象以创建新的Modul时（rootUygulama对象已在数据库中）：

{
    "adi": "Deneme Modülü 3",
    "kod": "DM1",
    "rootUygulama": {
        "id": 66,
        "adi": "Deneme Uygulaması",
        "kod": "DU",
        "uygulamaSahibi": "xxxxxx",
        "createdAt": "2020-07-24T21:18:47.874Z",
        "updatedAt": "2020-07-24T21:18:47.874Z",
        "moduller": [
        ]
    }
}

我收到错误消息：

[query] insert into "Uygulamalar" ("Adi", "Id", "Kod", "UygulamaSahibi", "createdAt", "updatedAt") values ('Deneme Uygulaması', 66, 'DU', 'szengin', '2020-07-25 00:18:47.874', '2020-07-25 00:18:47.874') returning "Id" [took 6 ms]
node_modules/mikro-orm/dist/utils/Logger.js:22
[query] rollback
node_modules/mikro-orm/dist/utils/Logger.js:22
(node:14344) UnhandledPromiseRejectionWarning: error: insert into "Uygulamalar" ("Adi", "Id", "Kod", "UygulamaSahibi", "createdAt", "updatedAt") values ($1, $2, $3, $4, $5, $6) returning "Id" - cannot insert into column "Id"
    at Parser.parseErrorMessage (d:\NODEJS\BildirimYonetimi\backend\node_modules\pg-protocol\dist\parser.js:278:15)
    at Parser.handlePacket (d:\NODEJS\BildirimYonetimi\backend\node_modules\pg-protocol\dist\parser.js:126:29)
    at Parser.parse (d:\NODEJS\BildirimYonetimi\backend\node_modules\pg-protocol\dist\parser.js:39:38)
    at Socket.<anonymous> (d:\NODEJS\BildirimYonetimi\backend\node_modules\pg-protocol\dist\index.js:8:42)
    at Socket.emit (events.js:311:20)
    at Socket.EventEmitter.emit (domain.js:482:12)
    at addChunk (_stream_readable.js:294:12)
    at readableAddChunk (_stream_readable.js:275:11)
    at Socket.Readable.push (_stream_readable.js:209:10)
    at TCP.onStreamRead (internal/stream_base_commons.js:186:23)
<node_internals>/internal/process/warning.js:32
(node:14344) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 2)
<node_internals>/internal/process/warning.js:32
(node:14344) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

当我按以下方式发送JSON时，对象已创建并成功插入数据库

{
    "adi": "Deneme Modülü 3",
    "kod": "DM1",
    "rootUygulama": 66
}

即使我将空级联数组设置为关系属性存储库，也尝试插入父对象并失败。

我在配置中缺少什么吗？

编辑：

对于我的Typescript客户端，我将如何定义rootUygulama属性？

export interface Modul {
  id: number;
  adi: string;
  kod: string;
  createdAt: Date;
  updatedAt: Date;
  rootUygulama: Uygulama;
  ekranlar: Array<Ekran>;
}

应该是

rootUygulama: Uygulama | number;

Answer 1

这与级联无关，行为正确。如果仅传递PK，则将其视为现有实体；如果传递对象，则将其视为新实体。这与是否设置PK无关，如果您想要该行为，则需要自己进行编程。

MikroORM基于更改集跟踪工作，因此只有托管对象（从数据库加载的实体）才能生成更新查询。如果要触发rootUygulama对象的更新查询，请使用em.nativeUpdate()。如果您仍然希望将有效负载与对象一起发送，但是您只关心PK，则还可以将该实体显式合并到EM（这样就可以对其进行管理，就像从db中加载它一样）。

const modul = DI.modulRepository.create(req.body);

// if we see PK, we merge, so it won't be considered as new object
if (modul.rootUygulama.id) {
  DI.em.merge(modul.rootUygulama);
  // here we could also fire the `em.nativeUpdate(Uygulama, modul.rootUygulama);` 
  // to fire an update query, but then you should use `em.transactional()` to have that update query inside the same TX as the flush
}

await DI.modulRepository.persistAndFlush(modul);
res.send(modul);

顺便说一句，我强烈建议不要禁用级联，除非您真正了解自己在做什么，因为默认设置是级联合并和持久化，这通常是您想要/需要的。

尝试插入具有嵌套父实体的实体时，无法插入“ Id”列错误

1 个答案: