本文介绍了如何检查 firebase 数据库值是否存在?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在将实时数据库与 Google 的 Firebase 结合使用,我正在尝试检查是否存在孩子.
I'm using the Realtime Database with Google's Firebase, and I'm trying to check if a child exists.
我的数据库结构如下
- / (root)
- /users/
–- /james/
-- /jake/
- /rooms/
-- /room1/
--- (room 1 properties)
-- /room2/
--- (room 2 properties)
我想检查room1是否存在.我尝试了以下方法:
I would like to check if room1 exists.I have tried the following:
let roomName:String = "room1"
roomsDB.child(roomName).observeSingleEventOfType(.Value) {
(snap:FIRDataSnapshot) in
let roomExists:Bool = snap.value != nil ? "TAKEN" : "NOT TAKEN"
}
在访问 snap.value
时,它返回该房间属性的 JSON,但我如何检查房间 (/rooms/room1/
) 是否存在开始?
In accessing snap.value
it returns a JSON of the properties of that room, but how would I check if the room (/rooms/room1/
) is there to begin with?
如果需要澄清,请评论
推荐答案
self.ref = FIRDatabase.database().reference()
ref.child("rooms").observeSingleEvent(of: .value, with: { (snapshot) in
if snapshot.hasChild("room1"){
print("true rooms exist")
}else{
print("false room doesn't exist")
}
})
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