How to query nested data in Firebase Database? - swift

Question

How can I make a query to get all bookings of all users that have timestamp in the range of 1519912278 ...1520689878 ? In Firebase docs it states that I can query deeply nested children.
According to this answer, it should work https://stackoverflow.com/a/47805607 , but it return null.
What is the flow of my User app? :
1. User singn up
2. When booking is made, it is saved at /Users/UID/stripe_customer_created_with_card/bookingNumber{booking object}
Why do I need all bookings located under /Users?:
There is a second app designed for Workers which can observe /Users node and each worker should be able to get bookings from /Users based on a timeStamp. For example a worker1382 can read bookings made by /Users from 16 March 2018 to 24 March 2018.
dbRef = FIRDatabase.database().reference().child("Users")
dbRef.queryOrdered(byChild: "TimeStampDateAndTime")
.queryStarting(atValue: "1519912278")
.queryEnding(atValue: "1520689878")
.observeSingleEvent(of: .value, with: { (snapshot: FIRDataSnapshot) in
print(snapshot.value) //returns null
}
Users
UID
cus_CRC50bSq7rXuHv //stripe customer id for the user
617643762 //booking number
TimeStampDateAndTime: "1521309610"
Postcode: "E14 9DS"
BookingNumber:"617643762"
Another question: The parent key of the booking object is equal to BookingNumber. If I replace the parent key 617643762 with TimeStampDateAndTime value 1521309610, would I be able to order the bookings by time stamp and ultimately get only the ones that are within a certain range 1519912278 ...1520689878? So, the path would look like Users/UID/cus/1521309610: {object goes here}
From Firebase Documentation
Queries can also be ordered by deeply nested children, rather than only children one level down. This is useful if you have deeply nested data like this:
{
"lambeosaurus": {
"dimensions": {
"height" : 2.1,
"length" : 12.5,
"weight": 5000
}
},
}
To query the height now, we use the full path to the object rather than a single key.
Now, my question is, what can't I do if I don't know the full path?
let ref = Firebase(url:"https://dinosaur-facts.firebaseio.com/dinosaurs")
ref.queryOrderedByChild("dimensions/height").observeEventType(.ChildAdded, withBlock: { snapshot in
if let height = snapshot.value["height"] as? Double {
println("\(snapshot.key) was \(height) meters tall")
}
})
EDIT 2
Initial Structure looks like this:
{
"Users" : {
"I50dHN7wPqPJClPfYDG76gXizdD2" : { //-> user?.uid of a logged in user
"cus_CRC50bSq7rXuHv" : {
"617643762" : {
"TimeStampDateAndTime" : "1521309610"
}
}
}
}
}
Modified structure:
{
"Users" : {
"I50dHN7wPqPJClPfYDG76gXizdD2" : {
"1521309610" : { // -> store timeStamp as the immediate child key of UID rather than the booking number
"TimeStampDateAndTime" : "1521309610",
"BookingNumber": "617643762"
}
}
}
}
{
"UsersProfile":{
"I50dHN7wPqPJClPfYDG76gXizdD2":{
"StripeCustomer":"cus_CRC50bSq7rXuHv", // -> store StripeCustomer on the UsersProfile
"Name": "John Doe"
}
}
}

Answer 1

You can query properties at a known path under each child node. So you can query dimensions/weight in the dinosaur sample, and you can query 617643762/TimeStampDateAndTime from your data.
But you can't query */TimeStampDateAndTime, since that's not a known path.
If you need to get a list of bookings in a date range across all users, you will need to modify your data structure to allow that query. For example, by adding a top-level list of bookings:
"Bookings": {
"book_617643762"
Customer: "cus_CRC50bSq7rXuHv"
TimeStampDateAndTime: "1521309610"
Postcode: "E14 9DS"
}
With this additional structure, you can then query:
dbRef = FIRDatabase.database().reference().child("Bookings")
dbRef.queryOrdered(byChild: "TimeStampDateAndTime")
.queryStarting(atValue: "1519912278")
.queryEnding(atValue: "1520689878")
.observeSingleEvent(of: .value, with: { (snapshot: FIRDataSnapshot) in
print(snapshot.value) //returns null
}