topic Re: I need an example of how to use a spatial relationship in a query. in ArcGIS API for Flex Questions

I need an example of how to use a spatial relationship in a query.

TracySchloss — Tue, 22 Jun 2010 21:06:59 GMT

I've seen posts where the goal is to let the user draw a polygon and select features within it. However, I have a twist on that. I have a find task that will select a particular district number. This is displayed to the user in a graphicslayer as a single polygon (will only ever have one polygon in it, it's just a highlight and I continually clear it out). I would then like to select all the points in another layer that fall within that district

I see that I can define my query to have a spatialRelationship of "SPATIAL_REL_WITHIN", but I can't find a good example of how I might use this. I"m not even sure this is my best approach. I've also been looking at the geometry service and the relations it returns.

Re: I need an example of how to use a spatial relationship in a query.

RobertScheitlin__GISP — Sat, 11 Dec 2021 18:07:13 GMT

Tracy,

Here is a complete sample app that using find to get the state polygon and then uses that polygon in the spatial query to get the cities that intersect it.

<?xml version="1.0" encoding="utf-8"?>
<mx:Application
    xmlns:mx="http://www.adobe.com/2006/mxml"
    xmlns:esri="http://www.esri.com/2008/ags"
    pageTitle="Find features in Map Layers"
    styleName="plain">

    <mx:Script>
        <![CDATA[
         import com.esri.ags.events.QueryEvent;
            import com.esri.ags.Graphic;
            import com.esri.ags.events.FindEvent;
            import com.esri.ags.geometry.Geometry;
            import com.esri.ags.tasks.Query;
            import com.esri.ags.tasks.FeatureSet;

            private function doFind():void
            {
                findTask.execute(myFindParams);
            }

            private function findCompleteHandler(event:FindEvent):void
            {
                myGraphicsLayer.clear();
                var graphic:Graphic;
                var query:Query = new Query();
                resultSummary.text = event.findResults.length + " State Found using Find Task";
                var resultCount:int = event.findResults.length;
                for (var i:Number = 0; i < resultCount; i++)
                {
                 query.returnGeometry = true;
                 query.outFields = ["CITY_NAME","POP1990"];
                 query.outSpatialReference = myMap.spatialReference;
                    graphic = event.findResults.feature;
                    query.geometry = graphic.geometry;
     graphic.symbol = sfsFind;
                    myGraphicsLayer.add(graphic);
                    queryTask.execute(query);
                }
            }
            
            private function queryCompleteHandler(event:QueryEvent):void
            {
             myGraphicsLayer.clear();
             var fset:FeatureSet = event.featureSet;
             resultSummary.text += " and " + fset.features.length + " cities found using spatial query."
    for each (var graphic:Graphic in fset.features)
    {
     graphic.symbol = smsFind;
     graphic.toolTip = graphic.attributes["CITY_NAME"] + " - Population: " + graphic.attributes["POP1990"]
     myGraphicsLayer.add(graphic);
    }
            }
        ]]>
    </mx:Script>

    <!-- Symbol for Find Result as Point -->
    <esri:SimpleMarkerSymbol id="smsFind" style="square" color="0xFFFF00" size="11" alpha="0.9">
        <esri:SimpleLineSymbol color="0x000000"/>
    </esri:SimpleMarkerSymbol>

    <!-- Symbol for Find Result as Polygon -->
    <esri:SimpleFillSymbol id="sfsFind" color="0xFFFF00" alpha="0.7"/>

    <!-- Find Task -->
    <esri:FindTask
        id="findTask"
        executeComplete="findCompleteHandler(event)"
        url="http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StatesCitiesRivers_USA/MapServer"
        />
    <!-- Query Task -->
    <esri:QueryTask
     id="queryTask"
     executeComplete="queryCompleteHandler(event)"
     url="http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StatesCitiesRivers_USA/MapServer/0"
        />
    <esri:FindParameters id="myFindParams"
        returnGeometry="true"
        contains="true"
        searchText="{fText.text}"
        layerIds="[2]"
        searchFields="['STATE_NAME']"
        />
    <mx:HBox width="100%" height="40" backgroundColor="0xDDDDFF" paddingTop="10" horizontalAlign="center">
        <mx:Text text="Search for names of States:"/>
        <mx:TextInput maxWidth="400" id="fText" enter="doFind()" text="Alabama"/>
        <mx:Button label="Find" click="doFind()"/>
    </mx:HBox>
    <mx:Text id="resultSummary" height="15"/>
        <esri:Map id="myMap">
            <esri:extent>
                <esri:Extent xmin="-126" ymin="24" xmax="-67" ymax="50">
                    <esri:SpatialReference wkid="4326"/>
                </esri:Extent>
            </esri:extent>
            <esri:ArcGISDynamicMapServiceLayer
                url="http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StatesCitiesRivers_USA/MapServer"/>
            <esri:GraphicsLayer id="myGraphicsLayer"/>
        </esri:Map>
</mx:Application>

Re: I need an example of how to use a spatial relationship in a query.

ShannonMartel — Tue, 30 Nov 2010 17:47:32 GMT

Is there a way to modify this code to allow for a spatial query of several different map services layers; Like floodplain, zoning, school district? I want to put the results in a datagrid. I assume there would be multiple querytasks but after that I am lost. I have this code in Flash 4. Thank you for your help.

Shannon

Re: I need an example of how to use a spatial relationship in a query.

tanyabisen — Thu, 16 Jun 2011 10:03:17 GMT

Hi Robert,

I am using the sample which you have given in this thread..Its working fine for few layers but the same code fails when i try to do attribute query on a particular layer. can u please help me with the issue.

I am using Bing maps as the basemap and the code shows wrong output for an attribute query.

Re: I need an example of how to use a spatial relationship in a query.

ZahidChaudhry — Thu, 16 Jun 2011 20:38:11 GMT

Hi Robert,

I am using the sample which you have given in this thread..Its working fine for few layers but the same code fails when i try to do attribute query on a particular layer. can u please help me with the issue.

I am using Bing maps as the basemap and the code shows wrong output for an attribute query.

Basemap doesnt matter, You need to make sure that you are getting geometry back from Find as that is the geometry you are using to query data..

Re: I need an example of how to use a spatial relationship in a query.

tanyabisen — Tue, 21 Jun 2011 11:03:11 GMT

Its returning a geometry but still it not working for few of my queries...

Re: I need an example of how to use a spatial relationship in a query.

RobertScheitlin__GISP — Tue, 21 Jun 2011 11:10:11 GMT

Tanya,

Does the layers that fails have the ObjectID and Shape fields visible?

Re: I need an example of how to use a spatial relationship in a query.

tanyabisen — Tue, 21 Jun 2011 11:16:43 GMT

Yes Robert,

I can give u d application link..n wen u select division nos D1-D5..find task is showing unusual behavior..for othr divisions..it is cmpletley wrking fine.. e.g D6,D45,D22.I have provided the link..

http://maps.ijanaagraha.org/Queries_15th/MergedQueries_Find/bin-debug/MergedQueries_Find.html.

I am struggling since 2 weeks to figure out the problem...anyhelp would be really appreciated

Re: I need an example of how to use a spatial relationship in a query.

RobertScheitlin__GISP — Tue, 21 Jun 2011 12:08:56 GMT

Tanya,

The issue is that the find task is the same as use a queryTask with a where clause like "Divisions LIKE 'D1*'". Is there a reason you are using Find Task instead of Query Task?

Re: I need an example of how to use a spatial relationship in a query.

tanyabisen — Wed, 22 Jun 2011 04:29:40 GMT

No..I tried using the query task also but still I am getting the same results for those first 5 divisions..and I am not able to figure put what is the problem.

Re: I need an example of how to use a spatial relationship in a query.

RobertScheitlin__GISP — Wed, 22 Jun 2011 10:57:46 GMT

Tanya,

When you use the QueryTask there is a "text" and a "where" attribute on the Query.

The text property will search the display field of your layer, it is a short hand for a where clause of: where YourDisplayField like '%SearchText%'.

You want to use the where attribute so you can have a specific SQL query statement.

Re: I need an example of how to use a spatial relationship in a query.

tanyabisen — Thu, 23 Jun 2011 03:57:38 GMT

Ok will try that again... I hope you went through the website link and could see the random behaviour for certain division numbers.. Thanks..will keep u posted if once it gets resolved..

Re: I need an example of how to use a spatial relationship in a query.

tanyabisen — Mon, 27 Jun 2011 03:42:49 GMT

Hey Robert, it worked with where clause..Guess some logic issue in Find Task but Query task works fine now..

Thanks a ton...

Regards,
Tanya