PROSAGA码农传奇-Mongodb-MongoDB，Mongoose和Apollo GraphQL在文档中定义

<div class =“post-text”itemprop =“text”>
  <P>
    的<strong>
      GraphQL方式是自定义标量类型，用于序列化/反序列化ObjectId
    </强>
  </p>
  <P>
    GraphQL架构
  </p>
   <pre>
    <code>
      scalar Date
scalar MongoObjectId
...
type User {
  username: String!
  email: String!
  permissions: [String!]!
  createdAt: Date!
  updatedAt: Date!
  enabled: Boolean!
  _id: MongoObjectId!
}

</code>
  </pre>
  <P>
    MongoObjectId标量类，灵感来源于
    <a href="https://docs.nestjs.com/graphql/scalars" rel="nofollow noreferrer">
      NestJs日期标量
    </A>
     和
    <a href="https://19majkel94.github.io/type-graphql/docs/scalars.html#custom-scalars" rel="nofollow noreferrer">
      TypeGraphQL ObjectId标量
    </A>
  </p>
   <pre>
    <code>
      import { Scalar } from '@nestjs/graphql';
import { Kind, ASTNode } from 'graphql';
import { ObjectId } from "mongodb";

@Scalar('MongoObjectId')
export class ObjectIdScalar {
  description = 'Mongo object id scalar type';

parseValue(value: string) {
    return new ObjectId(value); // value from the client
  }

serialize(value: ObjectId) {
    return value.toHexString(); // value sent to the client
  }

parseLiteral(ast: ASTNode) {
    if (ast.kind === Kind.STRING) {
      return new ObjectId(ast.value); // value from the client query
    }
    return null;
  }
}

</code>
  </pre>
  <P>
    之后，我们需要注册
     <code>
      ObjectIdScalar
    </code>
     作为提供者（就像
    <a href="https://docs.nestjs.com/graphql/scalars" rel="nofollow noreferrer">
      日期标量
    </A>
    ）并改变
     <code>
      _id
    </code>
     从
     <code>
      string
    </code>
     至
     <code>
      Type.ObjectID
    </code>
    。
  </p>
</DIV>

MongoDB，Mongoose和Apollo GraphQL在文档中定义_id类型