angular 使用密钥从 fire base 检索项目时发生 fire 2 错误

Question

当我尝试使用此格式的项目键从 Firebase 检索项目时，收到此错误。

getUser(id: string){
  console.log("current user id: " +  id);
  const user = this.af.database.object(`/userData/${id}`);
  this.userFromDb = this.af.database.object(`/userData/${id}`);
  user.subscribe(console.log);
  console.log("object from db: " + this.userFromDb);
  return this.userFromDb;
}

Error: database.refFromURL failed: First argument must be a valid firebase URL and the path can't contain ".", "#", "$", "[", or "]".

Answer 1

如错误消息中所示 $ 无效。 Firebase 完全支持 URL 之类的路径，所以这应该有效：

const user = this.af.database.object('/userData/' + id);