node.js - TypeORM 实体继承多对一关系

Question

我在 Node.JS 中使用 TypeORM 并想使用实体继承来实现 BaseRecord:

export abstract class BaseRecord {
  @CreateDateColumn({type: 'timestamp'})
  public created_at: Date;

  @UpdateDateColumn({type: 'timestamp'})
  public updated_at: Date;

  @ManyToOne(type => User, user => user.records_created)
  public created_by: User

  @ManyToOne(type => User, user => user.records_updated)
  public updated_by: User
}

我想扩展其他实体。这在删除 @ManyToOne 关系时按预期工作:

@Entity()
export class Address extends BaseRecord {
  @PrimaryGeneratedColumn()
  public id: number;

  @Column({ nullable: true, type: "text" })
  public alias: string;

  @Column({ type: "text" })
  public street_1: string;

  @Column({ nullable: true, type: "text" })
  public street_2: string;

  @Column({ type: "text" })
  public city: string;

  @Column({ type: "text" })
  public state: string;

  @Column({ type: "text" })
  public zip_code: string;

  @Column(type => GeoLocation)
  public geo_location: GeoLocation
}

有没有人遇到过这个或继承实体并拥有多对一关系的方法？

Answer 1

我建议使用组合而不是继承与 Embedded Entity

嵌入列是接受具有自己列的类并将这些列合并到当前实体的数据库表中的列。

您可以根据需要在嵌入式类中使用任意数量的列(或关系)。您甚至可以在嵌入类中嵌套嵌入的列。

import {Column} from "typeorm";

export class Assigned {
    @ManyToOne(type => User, user => user.records_created)
    public created_by: User

    @ManyToOne(type => User, user => user.records_updated)
    public updated_by: User
}

export class Dated {
    @CreateDateColumn({type: 'timestamp'})
    public created_at: Date;

    @UpdateDateColumn({type: 'timestamp'})
    public updated_at: Date;
}

然后使用它

import {Entity, PrimaryGeneratedColumn, Column} from "typeorm";
import {Assigned} from "./Assigned";
import {Dated} from "./Dated";

@Entity()
export class Address extends BaseRecord {
  // ...Other columns

  @Column(type => Assigned)
  assigned: Assigned;

  @Column(type => Dated)
  dated: Dated;
}

您可以根据需要在嵌入式类中使用任意数量的列(或关系)。
您甚至可以在嵌入类中嵌套嵌入的列。