如何随机化一些 Firebase Firestore 文档？ [复制]

Question

如何对集合中的文档进行随机排序。

这是我用来获取文档的功能，如何随机排序？

func fetchExplore() {
    let query = COLLECTION_POSTS.limit(to: 6)
    
    if let last = lastDoc {
        let next = query.start(afterDocument: last)
        next.getDocuments { snapshot, _ in
            guard let documents = snapshot?.documents, !documents.isEmpty else { return }
            self.lastDoc = snapshot?.documents.last
            self.posts.append(contentsOf: documents.compactMap({ try? $0.data(as: Post.self) }))
        }
    } else {
        query.getDocuments { snapshot, _ in
            guard let documents = snapshot?.documents else { return }
            self.posts = documents.compactMap({ try? $0.data(as: Post.self) })
            self.lastDoc = snapshot?.documents.last
        }
    }
    print("DEBUG: did fetch posts Explore")
}

Answer 1

这通常通过添加一个或两个浮点数来解决，您可以使用这些浮点数开始查询，例如：myDocsRef.whereField("random", isGreaterThanOrEqualTo: randomNumber).limit(1)

这个答案深入涵盖了它： Firestore: How to get random documents in a collection