How to query all IDs by a value from Firebase - swift

Question

Here is my data on Firebase
{
"messages" : {
"-KFdphRHtKSovYfCRYWE" : {
"senderId" : "95cf99d8-377b-4685-a8ee-2afe69a82419",
"text" : "Chechen"
},
"-KFdpisBYxFaSrm2CO67" : {
"senderId" : "425c9449-b3f7-4d21-b57c-4134b76712dd",
"text" : "sdd"
},
"-KFdpmKXuRrzDnl_JRmF" : {
"senderId" : "425c9449-b3f7-4d21-b57c-4134b76712dd",
"text" : "c dđcv"
},
"-KFdpnSJIX48yh1KpjFo" : {
"senderId" : "95cf99d8-377b-4685-a8ee-2afe69a82419",
"text" : "Bilbo,m"
}
},
"tasks" : {
"-KEPuc8aGpYLT0-NOo50" : {
"assignee" : "Kaito Kid",
"description" : "Task1",
"endTime" : "13:58 Thursday,07/04",
"from" : "Khuong Pham",
"priority" : 1,
"progress" : 10,
"startTime" : "13:58 Tuesday,05/04"
},
"-KFbsI0Q6WB5dWc90pIR" : {
"assignee" : "Khoa Pham",
"description" : "Task2",
"endTime" : "12:38 Thursday,21/04",
"from" : "Khuong Pham",
"priority" : 2,
"progress" : 0,
"startTime" : "12:38 Wednesday,20/04"
},
"-KFdngdnHyfG2pygRx3L" : {
"assignee" : "Khoa Pham",
"description" : "Task3",
"endTime" : "21:37 Wednesday,20/04",
"from" : "Khuong Pham",
"priority" : 0,
"progress" : 10,
"startTime" : "21:37 Tuesday,19/04"
},
"-KFdo-Q8HrrPZoaQcGRj" : {
"assignee" : "Khuong Pham",
"description" : "task4",
"endTime" : "23:44 Thứ Hai,18/04",
"from" : "Khoa Pham",
"priority" : 1,
"progress" : 7,
"startTime" : "21:41 Thứ Hai,18/04"
},
"-KFdpXmuGrLOBonb976Q" : {
"assignee" : "Khoa Pham",
"description" : "Task5",
"endTime" : "21:46 Friday,22/04",
"from" : "Khuong Pham",
"priority" : 2,
"progress" : 0,
"startTime" : "21:46 Tuesday,19/04"
},
"-KFdpdnPb_BVIDQ32Ym6" : {
"assignee" : "Khuong Pham",
"description" : "task6",
"endTime" : "23:46 Thứ Hai,18/04",
"from" : "Khoa Pham",
"priority" : 1,
"progress" : 0,
"startTime" : "23:46 Thứ Hai,18/04"
}
},
"typingIndicator" : {
"95cf99d8-377b-4685-a8ee-2afe69a82419" : false
},
"users" : {
"33ab67aa-6357-4f3e-aee8-623e294c7de2" : {
"dateJoin" : "19/04/2016",
"dateOfBirth" : "01/01/1990",
"firstName" : "Binh",
"gender" : "Male",
"group" : "PHP ",
"lastName" : "Nguyen",
"phone" : "0123456789",
"position" : "PHP Developer"
},
"425c9449-b3f7-4d21-b57c-4134b76712dd" : {
"dateJoin" : "01/01/2010",
"dateOfBirth" : "03/03/1990",
"firstName" : "Khoa",
"gender" : "Male",
"group" : "iOS Team",
"lastName" : "Pham",
"phone" : "0939133994",
"position" : "Senior iOS Developer"
},
"95cf99d8-377b-4685-a8ee-2afe69a82419" : {
"dateJoin" : "20/01/2016",
"dateOfBirth" : "29/10/1993",
"firstName" : "Khuong",
"gender" : "Male",
"group" : "iOS Team",
"lastName" : "Pham",
"phone" : "01655961231",
"position" : "iOS Developer"
},
"f88a6c6f-cbc8-4d37-a7d9-4ee4c3a6fd32" : {
"dateJoin" : "13/03/2016",
"dateOfBirth" : "01/01/1993",
"firstName" : "Kaito",
"gender" : "Male",
"group" : "Android Team",
"lastName" : "Kid",
"phone" : "0939133994",
"position" : "Android Developer"
}
}
}
I want to query all IDs which has "from" key that has value "Khuong Pham".
FIREBASE_REF.childByAppendingPath("tasks").observeEventType(.ChildAdded, withBlock: { (snapshot) -> Void in
print(snapshot.key) // all IDs
print(snapshot.value)
// Then Use this value to compare with "from" key has value "Khuong Pham"
// Then find the ID of it.
})
If I try this way, I have to spend more time to filter them.
Is there anyway to query faster that I can get the ID.
Any helps would be appreciated. Thanks.
UPDATE:
Here is the code:
func deleteTaskInFireBase() {
FIREBASE_REF.childByAppendingPath("tasks").queryOrderedByChild("from").observeEventType(.ChildAdded, withBlock: { snapshot in
if let from = snapshot.value["from"] as? String where (snapshot.value["from"] as? String) == "Khuong Pham" {
print("\(snapshot.key): \(from)")
}
})
}
Result is:
-KEPuc8aGpYLT0-NOo50: Khuong Pham
-KFbsI0Q6WB5dWc90pIR: Khuong Pham
-KFdngdnHyfG2pygRx3L: Khuong Pham
-KFdpXmuGrLOBonb976Q: Khuong Pham