go - Firestore Golang CollectionGroup删除单个子集合文档

Question

我可以使用CollectionGroup来访问所有满足条件的subCollection文档(记录)。然后，我可以循环访问以删除subCollection文档。问题是，尽管它可以完美运行，但确实是一个hack。有没有更好的方法使用Golang在Firestore中删除子集合？

    it := clientdb.CollectionGroup("mychildSubcollection").Where(...mycondition).OrderBy("myfield", firestore.Desc).Documents(context.Background())
for {
    doc, err := it.Next()
    if err == iterator.Done {
        break
    }
    if err != nil {
        // return err
    }
    
        // Strucure of the doc.Ref is --> &{0xc0000d6788 projects/myproj/databases/(default)/documents/myparentCollection/Ki8sr65sKIoZaCviCp/mychildSubcollection/JwvKbuyRTGx5wZaCviCp myparentCollection/Ki8sr65sKIoZaCviCp/mychildSubcollection/JwvKbuyRTGx5wZaCviCp JwvKbuyRTGx5wZaCviCp}        

    // fmt.Println(doc.Ref.ID)
    // fmt.Println(doc.Ref.Path)
    // fmt.Println(doc.Ref.Parent.Path)
    // fmt.Println(doc.Ref.Parent.ID)

    path1 := doc.Ref.Parent.Path
    path2 := path1[0: strings.LastIndex(path1, "myparentCollection")]
    path3 := strings.Replace(path1, path2, "", -1)
    clientdb.Collection(path3).Doc(doc.Ref.ID).Delete(context.Background())    // Regular collection command, to delete the subcollection
}

至少可以减少黑客的攻击，这也可能有所帮助->如您所见，doc.Ref提供了三个字段，这些字段显示了子集合文档ID(doc.doc的完整路径[doc.Ref.Path或doc.Ref.Parent.Path] .Ref.ID)，如何访问结构中的中间字段:“myparentCollection / Ki8sr65sKIoZaCviCp / mychildSubcollection / JwvKbuyRTGx5wZaCviCp”
谢谢!

Answer 1

以上被接受为解决方案。我要添加的唯一评论是，如果有更好的方法来提取集合的路径，它将更加通用。如您所见，我正在使用实际的集合名称[myparentCollection]来提取路径。效果很好，但是一般的东西会更好。

now := time.Now() // start deleting old ones, even ones that still have one second left to expire.
it := clientdb.CollectionGroup("mychildSubcollection").Where("expireafter", "<", now.Add(-1*time.Second)).OrderBy("myfield", firestore.Desc).Documents(context.Background())
    for {
        doc, err := it.Next()
        if err == iterator.Done {
            break
        }
        if err != nil {
            // return err
        }
        
            // Strucure of the doc.Ref is --> &{0xc0000d6788 projects/myproj/databases/(default)/documents/myparentCollection/Ki8sr65sKIoZaCviCp/mychildSubcollection/JwvKbuyRTGx5wZaCviCp myparentCollection/Ki8sr65sKIoZaCviCp/mychildSubcollection/JwvKbuyRTGx5wZaCviCp JwvKbuyRTGx5wZaCviCp}        
    
        // fmt.Println(doc.Ref.ID)
        // fmt.Println(doc.Ref.Path)
        // fmt.Println(doc.Ref.Parent.Path)
        // fmt.Println(doc.Ref.Parent.ID)
    
         // using some logic with strings below to get (extract) the collection path example: myparentCollection/Ki8sr65sKIoZaCviCp/mychildSubcollection, so the delete can use it and delete the particular document under the sub collection.
        path1 := doc.Ref.Parent.Path
        path2 := path1[0: strings.LastIndex(path1, "myparentCollection")]
        path3 := strings.Replace(path1, path2, "", -1)
        clientdb.Collection(path3).Doc(doc.Ref.ID).Delete(context.Background())    // Regular collection command, to delete the subcollection
    }