Cloud Firestore Swift:如何删除文档查询 [英] Cloud Firestore Swift: How to delete a query of documents

问题描述

我想删除我的集合用户名中所有具有UID字段作为当前用户ID的文档.到目前为止，这是我的代码:

I would like to delete all documents in my collection Usernames that has the field UID as the current user's ID. This is my code so far:

let uid = Auth.auth().currentUser!.uid
db.collection("Usernames").whereField("UID", isEqualTo: uid).delete

但是出现错误:

查询"类型的值没有成员删除".

Value of type 'Query' has no member 'delete'.

有什么特殊的技巧吗?谢谢！

Any special technique to this? Thanks!

推荐答案

指南介绍了如何删除数据.它还指出，不应从客户端删除整个集合.无法从查询中删除-您将必须获取所有文档并分别删除它们.如果存在大量文档的可能性，则应在服务器端进行操作.如果您确定只有少数几个，则可以查询它们，获取文档引用，然后删除它们，如下所示:

The guide shows you how to delete data. It also notes that deleting entire collections shouldn't be done from the client. There's no way to delete from a query -- you will have to get all the documents and delete them individually. If there is the potential for lots of documents, then you should do this server-side. If you know for sure there will only be a few, you can query them, get the doc references, and then delete them, like this:

let uid = Auth.auth().currentUser!.uid
db.collection("Usernames").whereField("UID", isEqualTo: uid).getDocuments() { (querySnapshot, err) in
  if let err = err {
    print("Error getting documents: \(err)")
  } else {
    for document in querySnapshot!.documents {
      document.reference.delete()
    }
  }
}

如果这是需要经常执行的操作，那么这是检查您的数据结构的好机会.也许进行一个收集，其中用户的用户名列在其uid下.然后，您可以查询单个文档，并使用它引用要删除的其他文档.

If this is something that will need to be done frequently, then this is a good opportunity to examine your data structure. Maybe make a collection where user's Usernames are listed under their uid. Then you could just query that single doc and use it to reference the other ones to delete.

Usernames: {
   byUID: {
        uid1: {
            funky_monkey: true,
            goodTimes: true
        }
   }
   byUsername: {
        funky_monkey: {
            UID: uid1
        }
   }
}

这只是一个建议.肯定还有其他选项可能更适合您的应用程序.

This is just one suggestion. There are definitely other options that may be better for your app.

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