Question

我是一个初学者，试图将json解析为猫鼬模型，以便我可以保存数据。

这是我的模特


const commentSchema = new Schema([{

  sectionId: String,comments:
 [{

      id: String,
      authorAvatarUrl: String,
      authorName: String,
      authorId: String,
      authorUrl: String,
      comment: String,

replies:
 [{
        id: String,
        authorAvatarUrl: String,
        authorName: String,
        authorId: String,
        authorUrl: String,
        comment: String,
        parentId: String
      }]
  }]

}]);

const Comment = mongoose.model("Comment", commentSchema);
module.exports = Comment;

这是我要映射的Json

var existingComments = [{
    "sectionId": "1",
    "comments":
 [{
        "id": 88,
        "authorAvatarUrl": "support/images/jon_snow.png",
        "authorName": "Jon Sno",
        "authorId": 1,
        "authorUrl": "http://en.wikipedia.org/wiki/Kit_Harington",
        "comment": "I'm Ned Stark's bastard",
        "replies":
 [{
          "id": 100,
          "authorAvatarUrl": "support/images/jon_snow.png",
          "authorName": "Jon Sno",
          "authorId": 1,
          "authorUrl": "http://en.wikipedia.org/wiki/Kit_Harington",
          "comment": "P.S.: I know nothing.",
          "parentId": 88
        }]
    }]
}]

在服务器端，我试图获得这样的评论

//Comment posted
router.post("/comments", (req, res, next) => {
  //Save the comment on database
  const [{
    sectionId,

comments:
 [{
      id,
      authorAvatarUrl,
      authorName,
      authorId,
      authorUrl,
      comment,

      replies: 
[{
        id,
        authorAvatarUrl,
        authorName,
        authorId,
        authorUrl,
        comment,
        parentId
      }]
    }]
  }] = req.body;


  const newComment = new Comment([{
    sectionId,comments:
 [{ id, }]

 }]);

  newComment
    .save()
    .then(comment => {
      res.redirect("/index");

    })

    .catch(err => {
      console.log(err);
    });

});

但是不起作用，任何帮助将不胜感激，因为我目前正试图更好地理解月球ODM。谢谢！！！

Answer 1

您的评论架构有点混乱。您创建了“评论”模式（请注意，这是单数形式），但是您试图将评论模式用作评论数组。

提示：保持架构和单数。

要在保持模型单一的同时实现所需的设计，可以尝试以下方法：

解决方案（1）：只有一个“部分”集合可以存储所有数据 注意：，尽管您有多个架构，但我们仅对SectionSchema进行建模，它将是我们唯一的集合，其中每个Section文档都包含您所需的所有信息。

const sectionSchema = new Schema({
    name: {
        type: String,
        required: [true, 'Section name is required']
    },
    comments: {
        type: [commentSchema]
    }
});

const replySchema = new Schema({
    //id: String, //not needed, mongoose will automatically add an "_id" property when you save 
    authorAvatarUrl: String,
    authorName: String,
    authorId: String,
    authorUrl: String,
    comment: String,
    parentId: String
});

const commentSchema = new Schema({
    //id: String, //not needed, mongoose will automatically add an "_id" property when you save 
    authorAvatarUrl: String,
    authorName: String,
    authorId: String,
    authorUrl: String,
    comment: String,
    replies:{
        type: [replySchema]
    }
});

module.exports =  mongoose.model("Section", sectionSchema);

在上述解决方案中，您仍然可以使用路由来仅处理特定的注释，例如：

router.get("/sections/:id") //gets the entire section document matching the ID
router.post("/sections/:id/comments/") //creates a new comment within section with matching ID. Simply push a new comment into the comments array
router.get("/sections/:id/comments/") //gets all the comments for this section. Simply return only the comments property of the section document.
router.get("/sections/:id/comments/:commentId") //gets a specific comment within a specific section. Filter the comments array to get the comment matching the commentId and then only return that.

etc..

最后的提示：还有其他方式可以对数据建模。这只是一个例子。例如，您可以有一个section集合和一个comment集合，其中注释文档存储一个部分ID，以指示该注释文档所涉及的部分。

看看https://mongoosejs.com/docs/subdocs.html和https://docs.mongodb.com/manual/core/data-modeling-introduction/，它可能有助于您了解数据建模的不同方式，以及猫鼬子文档的工作方式和使用方式。

我如何从这个JSON构建猫鼬模型

1 个答案: