firebase - 在 Firestore 文档中添加时间戳

Question

我是 Firestore 的新手。 Firestore 文档说...

Important: Unlike "push IDs" in the Firebase Realtime Database, Cloud Firestore auto-generated IDs do not provide any automatic ordering. If you want to be able to order your documents by creation date, you should store a timestamp as a field in the documents.

引用: https://firebase.google.com/docs/firestore/manage-data/add-data

那么我是否必须将 key 名称创建为 timestamp在文件中？或 created足以满足 Firestore 文档中的上述声明。

{
    "created": 1534183990,
    "modified": 1534183990,
    "timestamp":1534183990
}

Answer 1

firebase.firestore.FieldValue.serverTimestamp()

无论你想怎么称呼它都很好afaik。然后你可以使用 orderByChild('created')。
我在设置时间时也主要使用 firebase.database.ServerValue.TIMESTAMP

ref.child(key).set({
  id: itemId,
  content: itemContent,
  user: uid,
  created: firebase.database.ServerValue.TIMESTAMP 
})