问题描述
我有一个使用Python库Pyrebase设置的Firebase实时数据库。我正在尝试查询数据库以查找匹配的值。我的问题是我正在使用的查询不返回任何值，只是空括号。这是我用来检查匹配值func getTimeline(for configuration: SelectAccessoryIntent,in context: Context,completion: @escaping (Timeline<Entry>) -> ()) {
// id stores the uuid of the accessory that was chosen by the user using the dynamic Intent
if let id = configuration.accessory?.identifier {
// Step 2.: fetch the accessory
// hm is a HMHomeManager
let hm = HomeStore.shared.homeManager
// take a short nap until the connection to the local HomeKit instance is established (otherwise hm.homes will create an empty array on first call)
sleep(1)
let accessories = hm.homes.flatMap({ h in h.accessories })
if let a = accessories.filter({ a in a.uniqueIdentifier.uuidString == id }).first {
// a holds our HMAccessory
// Step 3.: select the characteristic I want
// obvIoUsly the real code chooses a specific characteristic
let s: HMService = a.services.first!
let c: HMCharacteristic = s.characteristics.first!
// Step 4.: read the characteristic's value
c.readValue(completionHandler: {err in
if let error = err {
print(error)
} else {
print(c.value ?? "nil")
}
// complete with timeline
completion(Timeline(entries: [RenderAccessoryEntry(date: Date(),configuration: configuration,value: c.value)],policy: .atEnd))
})
}
}
}
}
的查询。我似乎无法发现问题，我用readValue打印了整个数据库，它工作得很好。还要检查以确保传递了有趣的result = db.child("Users").order_by_child("Userid").equal_to( mUserID ).get()中的值，所以我不确定为什么只返回空括号，有什么想法吗？
db.child("Users").get() 
getID()解决方法
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