如何检索 firebase 集合中的最后一个文档.我还想获取文档字段值 [英] How to retrieve the last document in a firebase collection. I would also like to get the document fields value

问题描述

如何从 Cloud Firestore 集合中检索最后一个文档?我还想获取文档字段值.

How to retrieve the last document from a Cloud Firestore collection? I would also like to get the document fields value.

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推荐答案

如何检索 firebase 集合中的最后一个文档?

How to retrieve the last document in a firebase collection?

要解决这个问题，您需要使用如下所示的查询:

To solve this, you need to use a query that should look like this:

FirebaseFirestore rootRef = FirebaseFirestore.getInstance();
Query query = rootRef.collection("High Volume")
    .orderBy("Time", Query.Direction.DESCENDING)
    .limit(1);
query.get().addOnCompleteListener(/* ... */);

此查询将根据 time 属性对结果进行排序，并将结果限制为一个.

This query will order the results according to the time property and will limit the results to one.

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