在FireStore中订购数据 [英] Ordering Data In FireStore

问题描述

每个文档中都有数字数据...我正在使用此代码获取数据

I have numeric data each in every document... I am getting the data using this code

 db.collection('Stations').orderBy("station","asc").onSnapshot((querySnapshot) =>{
  this.setState({
    stations:querySnapshot.docs.map(doc => {
      return {
        id: doc.id,
        station:doc.data().station
      }
    })
  })
}); 

数据没有正确排列，如下所示:

And the data is not getting arranged properly as seen below:

推荐答案

您正在按使用字典顺序的字符串值进行排序.并且按照字典顺序，"100" 在"2" 之前.

You're ordering by string values, which use lexicographical ordering. And in lexicographical order "100" comes before "2".

要解决您的问题，请创建一个仅包含数值的字段，然后按该字段排序.另外，也可以填充数字，使它们都具有相同的长度，因为"002" 在"100 "之前.

To fix your problem, have a field with only the numerical value, and order by that field. Alternatively pad the numbers so they all have the same length, because "002" comes before "100".

另请参阅:

• Firestore如何进行查询操作字符串处理不同的数据类型?
• Firestore-降序订购

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