TypeORM：与实体中定义的 where 子句的关系

Question

我想创建一个 SalesOrder 实体，它与同一实体有 2 个 OneToMany 关系，但条件不同。

最终目标是检索这样的地址：

const salesOrder = await SalesOrder.findOne(1, {
    relations: ['receiverAddress', 'senderAddress']
});
console.log(salesOrder.receiverAddress)
console.log(salesOrder.senderAddress)

我不知道如何在 SalesOrder 实体中按类型过滤地址关系。

我想做这样的事情：

// SalesOrder.ts
@Entity()
export class SalesOrder extends BaseEntity {
  @Column()
  @PrimaryGeneratedColumn()
  id: number

  @OneToMany(SalesOrderAddress, salesOrderAddress => salesOrderAddress, {
    where: {
      type: 'receiver' // join condition salesOrderAddress.type = 'receiver'
    }
  })
  receiverAddress: SalesOrderAddress

  @OneToMany(SalesOrderAddress, salesOrderAddress => salesOrderAddress, {
    where: {
      type: 'sender' // join condition salesOrderAddress.type = 'sender'
    }
  })
  senderAddress: SalesOrderAddress
}

问题： where 子句不在 typeorm 装饰器中处理。

是否有可能得到类似的东西（不使用查询生成器）？

我知道我可以使用 2 个 OneToOne 关系，但这意味着 SalesOrder 数据库包含两个外键：receiverAddressId 和 senderAddressId。我更喜欢使用 OneToMany 关系，因为它允许在 SalesOrderAddress 上只有一个外键（例如 salesOrderId）。

Answer 1

在您的情况下，我会考虑创建自定义方法来获取所需的信息。检查该示例：

import { BaseEntity, Entity, PrimaryGeneratedColumn, Column, OneToMany, ManyToOne } from 'typeorm';

@Entity({ name: 'Address' })
export class Address extends BaseEntity {
  @PrimaryGeneratedColumn({ type: 'int' })
  id: number;

  @Column({ type: 'varchar', length: 20 })
  type: 'receiver' | 'sender';

  @Column({ type: 'nvarchar', length: 1024 })
  value: string;

  // Put the prop that connects this entity to SalesOrder
  @ManyToOne(SalesOrder, ref => ref.addresses)
  salesOrder: SalesOrder;
}

@Entity({ name: 'SalesOrder' })
export class SalesOrder extends BaseEntity {
  @PrimaryGeneratedColumn({ type: 'int' })
  id: number;

  // Put the prop that connects this entity to Address
  @OneToMany(Address, ref => ref.salesOrder)
  addresses: Address[];

  // Create a generic method to filter
  private static getTypeAddresses(id: number, type: 'receiver' | 'sender'): Promise<Address[]> {
    if (typeof id !== 'number') {
      throw new Error('The entity\'s id must be a number');
    }

    return Address
      .createQueryBuilder('Address')
      .select([ 'Address' ])
      .innerJoin(
        'Address.salesOrder',
        'SalesOrder',
        'SalesOrder.id = :id',
        { id: id }
      )
      .where(
        'type = :type',
        { type }
       )
      .getMany();
  }

  // Later, create your methods to obtain easifully your address
  static getReceiverAddresses(id: number): Promise<Address[]> {
    return SalesOrder.getTypeAddresses(id, 'receiver');
  }

  static getSenderAddresses(id: number): Promise<Address[]> {
    return SalesOrder.getTypeAddresses(id, 'sender');
  }

  getReceiverAddresses(): Promise<Address[]> {
    return SalesOrder.getTypeAddresses(this.id, 'receiver');
  }

  getSenderAddresses(): Promise<Address[]> {
    return SalesOrder.getTypeAddresses(this.id, 'sender');
  }
}

使用示例：

const salesOrder = await SalesOrder.findOne({ id: 1 });
console.log(await salesOrder.getReceiverAddresses());
console.log(await salesOrder.getSenderAddresses());

如果您不想为实体类添加方法，请考虑创建一个控制器类或其他更方便的过程。例如：

import { BaseEntity, Entity, PrimaryGeneratedColumn, Column, OneToMany, ManyToOne } from 'typeorm';

@Entity({ name: 'Address' })
export class Address extends BaseEntity {
  @PrimaryGeneratedColumn({ type: 'int' })
  id: number;

  @Column({ type: 'varchar', length: 20 })
  type: 'receiver' | 'sender';

  @Column({ type: 'nvarchar', length: 1024 })
  value: string;

  // Put the prop that connects this entity to SalesOrder
  @ManyToOne(SalesOrder, ref => ref.addresses)
  salesOrder: SalesOrder;
}

@Entity({ name: 'SalesOrder' })
export class SalesOrder extends BaseEntity {
  @PrimaryGeneratedColumn({ type: 'int' })
  id: number;

  // Put the prop that connects this entity to Address
  @OneToMany(Address, ref => ref.salesOrder)
  addresses: Address[];
}

export class SalesOrderCtrl extends SalesOrder {
  private static getTypeAddresses(id: number, type: 'receiver' | 'sender'): Promise<Address[]> {
    if (typeof id !== 'number') {
      throw new Error('The entity\'s id must be a number');
    }

    return Address
      .createQueryBuilder('Address')
      .select([ 'Address' ])
      .innerJoin(
        'Address.salesOrder',
        'SalesOrder',
        'SalesOrder.id = :id',
        { id: id }
      )
      .where(
        'type = :type',
        { type }
       )
      .getMany();
  }

  static getReceiverAddresses(id: number): Promise<Address[]> {
    return SalesOrder.getTypeAddresses(id, 'receiver');
  }

  static getSenderAddresses(id: number): Promise<Address[]> {
    return SalesOrder.getTypeAddresses(id, 'sender');
  }

  getReceiverAddresses(): Promise<Address[]> {
    return SalesOrder.getTypeAddresses(this.id, 'receiver');
  }

  getSenderAddresses(): Promise<Address[]> {
    return SalesOrder.getTypeAddresses(this.id, 'sender');
  }
}

使用示例：

const salesOrder = await SalesOrderCtrl.findOne({ id: 1 });
console.log(await salesOrder.getReceiverAddresses());
console.log(await salesOrder.getSenderAddresses());