是否可以在Cloud Firestore上查询Field并获取主集合字段以及具有子集合文档的子集合? [英] Is it possible to query Field and get main collection field and get sub collection with sub collection documents on cloud firestore?

问题描述

我需要查询字段并获取所有子集合和字段.有可能吗?

I need to query fields and get all sub-collections and fields. Is it possible?

      Stream<List<ChatFieldModel>> getChatField(String uid) {
        var ref = _db.collection('chats')
             .where('toUserId', isEqualTo: uid);
//Afterthat need to get sub collection with sub collection list of documents and main collection fields value. is it possible?

        return ref.snapshots().map((list) => list.documents
            .map((doc) => ChatFieldModel.fromForestore(doc))
            .toList());
      }

推荐答案

Firestore查询很浅.它们仅从正在查询的集合中返回文档(或者，如果使用集合组查询，则返回正在查询的集合).

Firestore queries are shallow. They only return documents from the collection that is (or, if you use collection group queries, the collections that are) being queried.

因此，如果您要查询聊天，则只会从该集合中获取文档.要从 messages 子集合加载文档，您将需要执行其他查询/读取操作.

So if you're querying chats, you will only get documents from that collection. To load documents from the messages subcollection you will need to perform an additional query/read operation.

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