如何在Firebase上展平数据 [英] How to flatten data on Firebase

问题描述

我正在开发一个应用程序，用户可以在其中发布类别内的产品.我正在使用Firebase，并且尝试将数据库中的数据展平，但是我不确定帖子与类别的连接.

I am developing an application where users post products inside categories. I am using firebase and I am trying to flatten the data on the database but I am not sure about the connections of the posts with the categories.

这是数据库设计:

"categories": {
  "category1": {
     "id": "1",
     "name":  "computers"  
   },
  "category2": {
     "id": "2",
     "name":  "Furniture"  
    },
  "category3: {
    "id": "3",
    "names":  "Books" 
   },
}
"users":{
  "email": "[e-mail]"       
  "posts": {
    "post1": {
       "id": "1"
       "title": "Selling my guitar",
       "categories": {
         "category1": "true"
        }
      }
  }

也许是这样

"categories": {
  "category1": {
     "id": "1",
     "name":  "computers",
     "posts": {
        "post1": true
     }
   },
  "category2": {
     "id": "2",
     "name":  "Furniture"
   },
  "category3": {
    "id": "3",
    "names":  "Books"
   },
}
"users": {
  "userid1": {
    "email": "[e-mail]" ,
    "posts": {
      "post1": "true"
    }
  }
 },

 "posts": {
    "post1": {
       "id": "1",
       "title": "Selling my guitar",
       "users": {
         "user1" : "true"
       },
       "categories": {
         "category1": "true"
        }
      }
  } 

因此，据我了解，我知道帖子应该是一个单独的实体，但是我不确定如何将它们联系起来.

So from what I learnt I know posts should be a separate entity but then I am not sure how to connect them.

让我知道如何改进该数据库.

Let me know how can I improve this database.

推荐答案

平移数据意味着您不混合实体类型.如果您查看当前的/users节点，现在将获得有关该用户(其电子邮件地址)和节点列表的信息.这是两种不同的实体类型，通常应放在单独的顶层列表中.

Flattening data means that you don't mix entity types. If you look at your current /users node, you now information about the user there (their email address) and a list of nodes. Those are two distinct entity types and should normally be in separate top-level lists.

"categories": {
  "category1": {
     "id": "1",
     "name":  "computers"  
   },
  "category2": {
     "id": "2",
     "name":  "Furniture"  
    },
  "category3: {
    "id": "3",
    "names":  "Books" 
   },
}
"users":{
  "userid1": {
    "email": "[e-mail]"       
  }
 },
 "posts": {
    "post1": {
       "id": "1"
       "title": "Selling my guitar",
       "categories": {
         "category1": "true"
        }
      }
  }

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