查询和Firebase中的位置(swift 3)
我可以如何在Firebase中进行查询? 在oracle sql的查询将是
"select * from users where username = "SomeUser"
我需要在Firebase,Swift 3中做同样的事情
你需要使用queryOrderedByChild
和queryStartingAtValue
。 这应该让你开始正确的方向。
let username = "SomeUser" FIRDatabase.database().reference.child("users").queryOrderedByChild("username").queryStartingAtValue(username).queryEndingAtValue(username).observeEventType(.ChildAdded, withBlock: { (snapshot) -> Void in }
Swift 3 && Firebase 3
我希望这会帮助你理解。 开始了
这是数据结构的例子:
这里是代码:
let username = "DavidMouse" // create searchRef or queryRef you name it let searchRef = FIRDatabase.database().reference().child("users").queryOrdered(byChild: "username").queryEqual(toValue: username) // search the username searchRef.observeSingleEvent(of: .value, with: { (snapshot) in guard snapshot.value is NSNull else { // yes we got the user let user = snapshot.value as! String print("\(user) is exists") return } // no there is no user with desire username print("\(username) is exists") }) { (error) in print("Failed to get snapshot", error.localizedDescription) }