topic Query task and function not drawing my polygons? in ArcGIS JavaScript Maps SDK Questions

Query task and function not drawing my polygons?

JeremySingh1 — Fri, 26 Apr 2019 18:22:00 GMT

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta
name="viewport"
content="initial-scale=1,maximum-scale=1,user-scalable=no"
/>
<title>Intro to FeatureLayer - 4.11</title>

var view = new MapView({
container: "viewDiv",
map: map,
center: [-73.98,40.74],
zoom: 13
});

/********************
* Add feature layer
********************/
// var featureLayer = new FeatureLayer({
// url:
// "https://services1.arcgis.com/JPUKRee8mEBfJ0K4/arcgis/rest/services/Subway/FeatureServer"
// });

//map.add(featureLayer);

var query = new Query();
query.where = "LINE ='BMT'";
query.outFields = [ "*" ];
query.returnGeometry = true;
var queryTask = new QueryTask({
url:"https://services1.arcgis.com/JPUKRee8mEBfJ0K4/arcgis/rest/services/Subway/FeatureServer"
});

queryTask.execute(query)
.then(function(result){
//console.log(result.features.length)

//*** ADD ***//
result.features.forEach(function(item){
var g = new Graphic({
geometry: item.geometry,
attributes: item.attributes,
symbol: {
type: "simple-marker",
color: "black",
width: 1.2,
style: "short-dot"
}

});
view.graphics.add(g);
});

});
});

</script>
</head>

Re: Query task and function not drawing my polygons?

RobertScheitlin__GISP — Fri, 26 Apr 2019 18:35:53 GMT

Jeremy,

You just need to set the outSpatialReference of the query class to be the same as the view.spatialReference.

Re: Query task and function not drawing my polygons?

JeremySingh1 — Fri, 26 Apr 2019 19:21:25 GMT

Thanks Robert, I still seem to have the issue. Im a bit new to this.

My changes are below:

var query = new Query();
query.where = "LINE ='BMT'";
query.outFields = [ "*" ];
query.outSpatialReference = view.spatialReference; *******Added this line.
query.returnGeometry = true;
var queryTask = new QueryTask({
url:"https://services1.arcgis.com/JPUKRee8mEBfJ0K4/arcgis/rest/services/Subway/FeatureServer"
});

Re: Query task and function not drawing my polygons?

RobertScheitlin__GISP — Sat, 11 Dec 2021 10:10:14 GMT

Jeremy,

You have several issue in your code on closer inspection.

1. The querytask url has to point to a specific layer in the service.

2. The where clause has to use fields and values that are actually in the service.

Your url has one layer so the url would be:

var queryTask = new QueryTask({
  url: "https://services1.arcgis.com/JPUKRee8mEBfJ0K4/arcgis/rest/services/Subway/FeatureServer/2"
});‍‍‍‍‍‍‍‍‍

But that layer does Not have a Line field in it so your query is invalid.

This is what it should be:

      var query = new Query();
      query.where = "SubwayCounts_2016_LINE ='BMT'";
      query.outFields = ["*"];
      query.returnGeometry = true;
      query.outSpatialReference = view.spatialReference;
      var queryTask = new QueryTask({
        url: "https://services1.arcgis.com/JPUKRee8mEBfJ0K4/arcgis/rest/services/Subway/FeatureServer/2"
      });

      queryTask.execute(query)
        .then(function(result) {
          //console.log(result.features.length)

          //*** ADD ***//
          result.features.forEach(function(item) {
            var g = new Graphic({
              geometry: item.geometry,
              attributes: item.attributes,
              symbol: {
                type: "simple-marker",
                color: "black",
                width: 1.2,
                style: "circle"
              }

            });
            view.graphics.add(g);
          });

        });
    });‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: Query task and function not drawing my polygons?

JeremySingh1 — Fri, 26 Apr 2019 20:13:58 GMT

Thank you! this works!