Firebase orderByChild(1) and filter by child two any solutions?

Question

Solution: As Frank already states, I had to create a separate filed for this sorting to work. As suggested, I created a filed "sortField" which combines the

"clubKey" + "_" + "startDate"

To modify my existing data sets, I made a quick java script function like this:

function createTestDataSet(){
    evd = dbAllEventsListRef;

    evd.on('child_added', function(snap, previous){
        console.log(snap.val());
        data = snap.val();
        data.sortField = data.clubKey + "_" + data.startDate;
        testDiv = document.getElementById("divCarSummary");
        testDiv.innerHTML = testDiv.innerHTML + "<br/>"+data.sortField;
        evd.child(snap.key).set(data);
    });
}

I tested this using the following code:

function testSort(){
    key = "manualClubKey-1";
    testEvents = dbTesting.child('eventList').orderByChild("sortField").startAt(key+"_").endAt(key+"a");
    testEvents.on('child_added', function(snap, previous){
        data = snap.val();
        testDiv = document.getElementById("divCarSummary");
        testDiv.innerHTML = testDiv.innerHTML + "<br/>"+data.startDate+", "+data.name+", "+snap.key+", "+data.clubKey;

        console.log(snap.val());
    });
}

The tricky part was, that the manual for "endAt" states:

The ending point is inclusive, so children with exactly the specified value will be included in the query

But this does not seem to be true. If I give the same value for startAt() and endAt(), I get no results. So I modified the query, that I look for the "clubKey" + the separator. For the Separator I gave a character right after the "_". thus it works like a charm.

I modified my android Code, so every time the startDate, or the clubKey is written, I update the "sortFiled", small change, works like a charm.

Original Question I have some event data. Sample data:

{
  "modeltruckerManualEventID-96" : {
    "canceled" : false,
    "clubKey" : "manualClubKey-1",
    "endTime" : "17:00:00",
    "eventOpenForWeightData" : false,
    "link" : "",
    "locationID" : "manualLocationID-4",
    "name" : "Fahrtag TuHaKi",
    "startDate" : "2012-06-17",
    "startTime" : "10:00:00"
  },
  "modeltruckerManualEventID-97" : {
    "canceled" : false,
    "clubKey" : "manualClubKey-2",
    "endTime" : "17:00:00",
    "eventOpenForWeightData" : false,
    "link" : "",
    "locationID" : "manualLocationID-4",
    "name" : "Fahrtag TuHaKi",
    "startDate" : "2012-06-17",
    "startTime" : "10:00:00"
  },
  "modeltruckerManualEventID-98" : {
    "canceled" : false,
    "clubKey" : "manualClubKey-2",
    "endTime" : "16:00:00",
    "eventOpenForWeightData" : false,
    "link" : "",
    "locationID" : "manualLocationID-4",
    "name" : "Fahrtag TuHaKi",
    "startDate" : "2012-03-11",
    "startTime" : "10:00:00"
  },
  "modeltruckerManualEventID-99" : {
    "canceled" : false,
    "clubKey" : "manualClubKey-1",
    "endTime" : "16:00:00",
    "eventOpenForWeightData" : false,
    "link" : "",
    "locationID" : "manualLocationID-4",
    "name" : "Fahrtag TuHaKi",
    "startDate" : "2011-11-27",
    "startTime" : "10:00:00"
  }
}

I now want to filter, so I only get events from one "clubKey" which I could achieve using:

.orderByChild("clubKey").equalTo("manualClubKey-1")

That works fine.

But is there any way, that I can order the results also by child "startDate"?

So I want to have the filtered results ordered by startDate finally.

As far as I know this does not work.

I use Firebase on Android with Firebase UI.

Any Ideas how to achieve that?

I do not want to restructure the data or duplicate it further.

Hope there is a way, maybe force the ordering already on storage?

You will either have to order the data client-side or create a property that combines the values of `clubKey` and `startDate`. For example: `"clubKey_startDate": "manualClubKey-1_2011-11-27"`. See http://stackoverflow.com/questions/26700924/query-based-on-multiple-where-clauses-in-firebase — Frank van Puffelen, May 11 '17 at 04:07
Thank, but I do not see, how do I get all "manualClubKey-1" with ANY startDate, but ordered by startDate. Or is there a trick using startAt and endAt. On the Link given I did not see a solution to my problem, where it seems to look similar. — Juergen S., May 11 '17 at 19:34
Your question seemed to be how to get users with `club == "manualClubKey-1"` order by `startDate`. You'll need to create a composite property for that and then `ref.orderByChild("clubKey_startDate").startAt("manualClubKey-1").endAt("manualClubKey-2")` — Frank van Puffelen, May 12 '17 at 04:41
I think the confusing part here is, that I tryed to use the same value for startAt and endAt, as the manual states for startAt "=>" and for endAt "<=", but it seems endAt only does "<" lower and not a lower and equal. dbTesting.child('eventList').orderByChild("sortField").startAt("manualClubKey-1").endAt("manualClubKey-2"); works, but dbTesting.child('eventList').orderByChild("sortField").startAt("manualClubKey-1").endAt("manualClubKey-1"); does not. I will look into this aproach, as I only did a quick javascript testing — Juergen S., May 12 '17 at 16:03

score 0 · Answer 1 · answered May 11 '17 at 00:57

0

If you want to orderByChild(especificdate), is not possible without restructuring the data.

However, lets say you want to get the latest added nodes, just use limitToLast(numberOfChildren)

answered May 11 '17 at 00:57

Martin De Simone

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Firebase orderByChild(1) and filter by child two any solutions?

1 Answers1