topic Definition Query for FeatureLayer in Qt Maps SDK Questions

Definition Query for FeatureLayer

AndyWright — Sun, 19 Apr 2015 20:11:22 GMT

I would like to perform a definiton query against a FeatureLayer that I've loaded into my map from a local geodatabase. Reading through the help, it seems that definition queries are only supported against FeatureServiceLayers. The FeatureLayerInfo object has the definitionExpression property, but takes a url to set the feature layer's endpoint. So I don't see any way to get at the FeatureLayerInfo property for a FeatureLayer from a local geodatabase.

What I do see on a FeatureLayer is the setFeatureVisible property, which looks like it does the same sort of thing that a definition query would. The problem here is I would have to do this one feature at a time. That doesn't seem very efficient.

Hopefully I'm way off base here. Does anyone have an example they could post showing how to do a definition query against a local gdb feature layer?

Re: Definition Query for FeatureLayer

LucasDanzinger — Mon, 20 Apr 2015 21:59:46 GMT

Andy-

It looks like the issue is that we need a definitionExpression property on the FeatureLayer, but do not have it in C++ or QML. The definitionExpression on the GeodatabaseFeatureServiceTable is meant to work with that class only, and isn't supported with the GeodatabaseFeatureTable. I have logged an issue internally to get this added to the FeatureLayer. If you are creating your geodatabase from a service, then you could provide a query when generating the geodatabase. Otherwise, if you are generating the geodatabase through ArcMap, then I unfortunately cannot think of an easy workaround. What you suggested could work, but will likely be very time consuming.

-Luke

Re: Definition Query for FeatureLayer

AndyWright — Tue, 21 Apr 2015 15:45:18 GMT

We are creating the geodatabase from a service, but we can't blanketly set one def query and be done. The def query needs to change based on what assignments the user is currently working. Even being able to pass a list of ids into the setFeatureVisible would be better. I am going to try to do the loop thing and see how it performs, but this enhancement would be a big win for the next release.

Thanks for your feedback Lucas ...

Re: Definition Query for FeatureLayer

AndyWright — Tue, 21 Apr 2015 18:51:48 GMT

Lucas,

I just implemented the setFeatureVisible stuff and it actually doesn't perform half bad. Looks like it will be a decent workaround until you get the def query stuff implemented.

Re: Definition Query for FeatureLayer

LucasDanzinger — Tue, 21 Apr 2015 18:58:16 GMT

Thanks for the update, Andy. If you have a simple example of what you did and don't mind posting, it may be helpful for others if you copy a little snippet up here. If it's too much work and very specific to your app, then no worries though!

Re: Definition Query for FeatureLayer

AndyWright — Tue, 21 Apr 2015 19:43:02 GMT

Yeh no problem. This is a quick and dirty test harness, but it shows at a basic level how to implement this type of thing.

import QtQuick 2.3

import QtQuick.Controls 1.2

import ArcGIS.Runtime 10.25

import ArcGIS.Extras 1.0

ApplicationWindow {

    id: appWindow

    width: 800

    height: 600

    title: "DefQueryTest"

    property string m_LocalDataPath: System.userHomeFolder.path + "/Documents"

    property string globalId: '{AA225F49-C337-4163-A1D6-92CE6B64052D}'

    Map {

        anchors.fill: parent

        focus: true

        ArcGISTiledMapServiceLayer {

            url: "http://server.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer"

        onStatusChanged: {

           if (status === Enums.MapStatusReady)

              assignmentGdb.path = m_LocalDataPath + "/EpochField/Data/DamageAssessment/Assignment5763-E0927.geodatabase"

        FeatureLayer {

            id: zbFeatLyr

            featureTable: zbFeatTab

    Geodatabase {

        id: assignmentGdb

    GeodatabaseFeatureTable {

        id: zbFeatTab

        geodatabase: assignmentGdb.valid ? assignmentGdb : null

        featureServiceLayerName: "Zone Buffer"

        property string defQueryType

        onGeodatabaseFeatureTableValidChanged: {

            if (geodatabaseFeatureTableValid) {

                console.log("Zone Buffer feature table is initialized ...")

        onQueryFeaturesStatusChanged: {

            if (queryFeaturesStatus === Enums.QueryFeaturesStatusCompleted) {

                console.log("QUERY RETURNED WITH " + queryFeaturesResult.featureCount + " FEATURES!!!");

                var iterator = queryFeaturesResult.iterator;

                while (iterator.hasNext()) {

                    //  Get feature

                    var currentFeat = iterator.next();

                    var waGlobalId = currentFeat.attributeValue("WORK_ASSIGNMENT_GLOBALID");

                    if (defQueryType === "QUERY") {

                        if (waGlobalId === globalId) {

                            console.log("WE HAVE A MATCH!!!");

                            zbFeatLyr.setFeatureVisible(currentFeat.uniqueId, true);

                        else {

                            zbFeatLyr.setFeatureVisible(currentFeat.uniqueId, false);

                    else if (defQueryType === "RESET") {

                        zbFeatLyr.setFeatureVisible(currentFeat.uniqueId, true);

                console.log("DONE");

    Query {

        id: layerQuery

        returnGeometry: false

        outFields: ["OBJECTID", "WORK_ASSIGNMENT_GLOBALID"]

    Button {

        text: "Query"

        anchors {

            top: parent.top

            right: parent.right

            margins: 10

        onClicked: {

            zbFeatTab.defQueryType = "QUERY";

            layerQuery.where = "1=1";

            zbFeatTab.queryFeatures(layerQuery);

    Button {

        text: "Reset"

        anchors {

            top: parent.top

            left: parent.left

            margins: 10

        onClicked: {

            zbFeatTab.defQueryType = "RESET";

            layerQuery.where = "1=1";

            zbFeatTab.queryFeatures(layerQuery);