graphql - Typegraphql+TypeORM : save/update an array of entities

Question

我有一个 graphql 服务器和一个 role 表，我想在一个突变中保存多个角色。

我搜索了很多，但一无所获。

我该如何做:

mutation {
  addRoles (roles: [
    {
      name: "role1",
      description: "role 1"
    },
    {
      name: "role2",
      description: "role 2"
    },
    ...
  ])
}

也就是说，如何实现addRoles和updateRoles解析器？

for 循环是唯一的选择吗？是否可以在一次数据库调用中保存所有角色？

角色模型:

@Entity("role")
@ObjectType()
export class Role extends BaseEntity {
  @Field((type) => Number)
  @PrimaryGeneratedColumn()
  readonly id!: number;

  @Field()
  @Column({ length: 64 })
  name!: string;

  @Field({ nullable: true })
  @Column({ length: 512, nullable: true })
  description!: string;
}

并添加和更新解析器:

@Resolver((of) => Role)
export class RoleResolver {

  @Mutation((returns) => Boolean)
  async addRole(
    @Arg("role") role: AddRoleInput
  ): Promise<Boolean> {
    const roleExists = await Role.count({ name: role.name });
    if (roleExists > 0)
      throw new Error(`Role with name "${role.name}" already exists!`);

    const newRole = Role.create(role);
    await newRole.save();
    return true;
  }

  @Mutation((returns) => Boolean)
  async updateRole(
    @Arg("role") role: UpdateRoleInput
  ): Promise<Boolean> {
    const oldRole = await Role.findOneOrFail(role.id);
    Object.assign(oldRole, role);
    await oldRole.save();
    return true;
  }
}

以及AddRoleInput 和UpdateRoleInput

@InputType({ description: "New Role Argument" })
export class AddRoleInput implements Partial<Role> {
  @Field()
  name!: string;

  @Field({ nullable: true })
  description?: string;
}

@InputType({ description: "Update Role Argument" })
export class UpdateRoleInput implements Partial<Role> {
  @Field()
  id!: number;

  @Field()
  name!: string;

  @Field({ nullable: true })
  description?: string;
}

Answer 1

我通过反复试验找到了答案。如果有人遇到同样的问题，我会在这里发布:

@Resolver((of) => Role)
export class RoleResolver {

  @Mutation((returns) => Boolean)
  async addRoles(
    @Arg("roles", type => [AddRoleInput]) roles: AddRoleInput[]
  ): Promise<Boolean> {

    // also checks at front
    const roleExists = await Role.count({
      name: In(roles.map((role) => role.name)),
    });
    if (roleExists > 0)
      throw new Error(`Role name conflict!`);
 
    const newRoles = []
    for (let i=0, i < roles.length, i++) {
        const newRole = Role.create(roles[i]);
        newRoles.push(newRole);
    }

    // this is the solution
    // turns out an entity class can be used to save instances
    // failed to found this in the docs though
    await Role.save(newRoles);

    return true;
  }
...
}

如果有更好的答案，我会保持悬赏。