Retrieve data from an unknown child name with Firebase and Swift - swift

Question

I'm using Firebase as the database for my IOS app. I want to retrieve data of several users from the database.
Here is my database organization:
Users
UserID1
Location: value1
UserID2
location: Value2
...
I want to retrieve the location data of all the users of the database.
The basic snapshot fonction
ref.child("Users").child("").child("Location").observe(.value, with: {
snapshot in
for Location in snapshot.children {
self.locationsArray.append((Location as AnyObject).key)
}
print(self.locationsArray)
})
My question is: how can I retrieve all the Locations even if I don't specify (I can't) the userID that is the name of a child before? Thanks.

Answer 1

Here's a code snippet that retrieves and prints the uid of each user and their location.
We can further refine our results with a .query
let usersRef = ref.child("users")
usersRef.observeSingleEvent(of: .value, with: { (snapshot) in
for snap in snapshot.children {
let userSnap = snap as! FIRDataSnapshot
let uid = userSnap.key //the uid of each user
let userDict = userSnap.value as! [String:AnyObject] //child data
let location = userDict["Location"] as! String
print("key = \(uid) is at location = \(location)")
}
})

Answer 2

It is not possible with Firebase to retrieve just the Location.
There are a lot of option, but I see two that fits better in your case:
Get everything from all users, and then manage in your code what you want;
Create another dictionary only with users id and location.
The second option would be like:
UsersLocation
UserID1:Location1
UserID2:Location2
So every time you change your main array you need to change this too.