Typegraphql+TypeORM:保存/更新实体数组

Question

我有一个graphql服务器和一个role表，我想在一个变体中保存多个角色。

我找了很多，但什么也没找到。

我如何做一些事情，比如：

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

换句话说，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DB调用中保存所有角色？

role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;
}

以及添加和更新解析器：

@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

我设法通过试错找到了答案。我会把它贴在这里，以防有人有同样的问题：

@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;
  }
...
}

我会保持悬赏以防有更好的答案。

Answer 2

您需要做的要点是在您的模式中的突变类型上定义一个addRoles字段。例如

export const RoleSchema = gql`
  type Role {
    id: Int
    # Other fields omitted for brevity
  }

  extend type Mutation {
    # This should already exist
    addRole(role: AddRoleInput!): Role!

    # To accept multiple Input Types, use the List construct
    addRoles(roles: [AddRoleInput!]!): [Role!]
  }
`;

然后在解析器中定义addRoles并调用相应的接口。