非规范化架构？

Question

猫鼬模式：

const postSchema = new mongoose.Schema({
    title: { type: String },
    content: { type: String },

    comments: {
        count: { type: Number },
        data: [{
            author: {
                type: mongoose.Schema.Types.ObjectId,
                ref: 'User'
            },
            content: { type: String },
            created: { type: Date },

            replies: [{
                author: {
                    type: mongoose.Schema.Types.ObjectId,
                    ref: 'User'
                },
                content: { type: String },
                created: { type: Date },
            }]
        }]
    }
})

我不想规范化评论和回复，因为：

我总是需要 post 评论（一次阅读）
我永远不会使用评论来查询或排序任何东西
创建、更新和删除 post 带注释（文档锁定）

如果我将它归一化，我将不得不：

从数据库中获取post
从数据库获取评论
获得对每个条评论的回复

这是 MongoDB 的最大优势之一：专门对数据进行分组以满足您的应用程序数据需求，但 GraphQL 和 Relay.js 似乎不支持？

问题：

有没有办法让评论嵌套在单个 post 对象中（或者至少让回复嵌套在单个评论中）以便在一次读取中获得全部内容？

GraphQL 架构：

const postType = new GraphQLObjectType({
    name: 'Post',
    fields: () => ({
        id: globalIdField('Post'),
        title: { type: GraphQLString },
        content: { type: GraphQLString },

        comments: {

            // ?????

        }
    }),
    interfaces: [nodeInterface],
})

更新：

const postType = new GraphQLObjectType({
    name: 'Post',
    fields: () => ({
        id: globalIdField('Post'),
        title: { type: GraphQLString },
        content: { type: GraphQLString },

        commentCount: { type: GraphQLInt },
        comments: { type: new GraphQLList(commentType) }
    }),
    interfaces: [nodeInterface]
})

const commentType = new GraphQLObjectType({
    name: 'Comment',
    fields: () => ({
        content: { type: GraphQLString },
        created: { type: GraphQLString },
        author: {
            type: userType,
            resolve: async (comment) => {
                return await getUserById(comment.author)
            }
        },
        replies: {
            type: new GraphQLList(commentType),
            resolve: (comment) => {

                // Log is below
                console.log(comment)

                // Error only occurs if I return it!
                return comment.replies
            }
        }
    })
})

日志 (comment):

{ 
  author: 'user-1',
  created: '05:35'
  content: 'Wow, this is an awesome comment!',
  replies:
     [{ 
       author: 'user-2',
       created: '11:01',
       content: 'Not really..',
     },
     {  
       author: 'user-1',
       created: '11:03',
       content: 'Why are you so salty?',
     }]
}

Answer 1

This is one of the biggest strengths of MongoDB: to group your data specifically to suit your application data needs but GraphQL and Relay.js doesn't seem to support that?

GraphQL 确实支持您尝试做的事情。在进入细节之前，我们需要记住 GraphQL 是关于公开数据，而不是关于我们如何存储数据。我们可以以任何我们喜欢的方式存储——规范化或非规范化。我们只需要告诉 GraphQL 如何获取我们在 GraphQL 模式中定义的数据。

Is there a way to get comments nested inside of a single post object (or at least get replies nested inside of a single comment) in order to get the whole thing in a single read?

是的，这是可能的。您只需将评论定义为列表。但是，GraphQL 不支持 GraphQL 对象类型中的任意类型的字段。因此，我们需要定义单独的 GraphQL 类型。在您的猫鼬模式中，comments 是一个具有 count 条评论和 data 条评论的对象。 data 属性是另一类对象的列表。因此，我们需要定义两个 GraphQL 对象 - Comment 和 CommentList。代码如下所示：

const commentType = new GraphQLObjectType({
  name: 'Comment',
  fields: () => ({
    author: { type: GraphQLString },
    content: { type: GraphQLString },
    created: { type: GraphQLString },
    replies: { type: new GraphQLList(commentType) },
  }),
});

const commentListType = new GraphQLObjectType({
  name: 'CommentList',
  fields: () => ({
    count: {
      type: GraphQLInt,
      resolve: (comments) => comments.length,
    },
    data: {
      type: new GraphQLList(commentType),
      resolve: (comments) => comments,
    },
  }),
});

const postType = new GraphQLObjectType({
  name: 'Post',
  fields: () => ({
    id: globalIdField('Post'),
    title: { type: GraphQLString },
    content: { type: GraphQLString },

    comments: {
      type: commentListType,
      resolve: (post) => post.comments,
    }
  }),
  interfaces: [nodeInterface],
});

I don't want to normalize comments and replies because:

I will always need post comments together (read in a single go)

I will never use comments to query or sort anything

It's so much easier to create, update and delete post with comments (document locking)

以上述方式定义 post 和注释 GraphQL 对象类型让您：

一起阅读所有 post 条评论
不要使用注释查询，因为它甚至没有id字段。
使用您喜欢的数据库以您喜欢的任何方式实施评论操作。 GraphQL 与它无关。

非规范化架构？

Denormalized schema?

node.js

mongodb

mongoose

relayjs

graphql-js

更新：