Firestore按领域分组 [英] Firestore Group by field

问题描述

下面是我的Firestore集合结构

Below is my firestore collection structure

我的vue获取数据的方法

My vue method to get data

fetchResults(){
  db.collection('data').onSnapshot((querySnapShot)=>{
    let results = [];
    querySnapShot.forEach(doc=>{
      results.push(doc.data())
    })
    this.record=results;
  })
}

我想要的是像group by ID and order by sec_id desc这样的文档进行查询.

What I want is to query in the document like group by ID and order by sec_id desc.

我该如何查询?

这样我就可以按ID字段对文档进行分组.

So that I will get document grouped by ID field.

推荐答案

作为NoSQL类型数据库，Cloud Firestore不提供任何聚合查询，例如分组，求和，最大值等.您必须在自己的数据库中执行这些操作.客户代码.对于您的情况，这意味着您将必须查询集合中的所有文档，然后按所需的字段对它们进行分组.另外，您可以维护一个单独的预分组文档集合来满足您的查询. (在NoSQL类型的数据库中，这样的数据复制很常见.)

As a NoSQL type database, Cloud Firestore doesn't offer any aggregation queries such as grouping, sum, max, etc. You have to perform these operations in your client code. For your case, this means you will have to query for all the documents in the collection, then group them by whatever fields you want. Alternatively, you can maintain a separate collection of pre-grouped documents to satisfy your query. (Duplicating data like this is common in NoSQL type databases.)

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