How can I retrieve data with queryEqualToValue in auto id child. Firebase-iOS - swift

Question

As my question. I can't retrieve data from firebase when I try to use "queryEqualToValue" with auto id key.
self.ref.child(..my child..).queryOrderByChild("name").queryEqualToValue("my name")
auto child id above child "name".
Edit: for my json tree
Students
(auto id)
name
first name
nick name
My real data doesn't like this but this's for example structure.
I really want to check equal to "first name".
Here's my code
let ref = FIRDatabase.database().reference()
ref.child("Students").queryOrderedByChild("name").queryEqualToValue("Jason bourne").observeEventType(.Value, withBlock: { snapshot in
print("value : " + snapshot.value)
}

Answer 1

Given your realtime database looks something like this:
{
"students": {
1: {
"name": {
"first_name": "Nathapong",
"nick_name": "Oniikal3"
}
}
}
}
You can observe the students path with the event type ChildAdded and order the query by child key name/first_name. Then you can use queryEqualToValue to find students with a particular first name.
let ref = FIRDatabase.database().referenceWithPath('students').queryOrderByChild("name/first_name").queryEqualToValue("Nathapong")
ref.observeSingleEventOfType(.ChildAdded, block: { snapshot in
print(snapshot)
})

Answer 2

This code should work. Check for names if I made any mistakes and insert your data.
self.ref.child("Students").child("name").queryOrderedByChild("first name").queryEqualToValue("my name").observeSingleEventOfType(.Value) { (snapshot: FIRDataSnapshot) in
print(snapshot.value)
}

Answer 3

Before use queries with child, you need to specify this using ".indexOn":["name"] in Database Rules. See documentation for examples
{
"rules":{
".write": "true",
".read": "true",
"Students": {
"$key": {
".indexOn":["name"]
}
}
}
}
Your read/write rules can go where you need it. .indexOn is just like another rule, alongside with .validate