Spatial Query

RobertPincus

I want to select a polygon in one layer, run a spatial query on another layer and list the attributes of the selected features.

For example, using the service at "http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Demographics/ESRI_Census_USA/MapServer/", I can select the State of California's feature (layer 5). I then want to take this feature and run a spatial query on the Counties layer (layer 3) and list the names of the selected counties.


Thanks,
Robert

TracySchloss

The first query function finds the geometry, which is then passed to another querytask, this one based on geometry as a search instead of by attributes.  In my example, I am using region, but you should be able to follow the logic.  I have a dropdown list instead of a text input field to make sure the input is valid.

function findRegion(){         var e = document.getElementById("regionSelect");  //the component name of the region selection         var regionQueryTask = new esri.tasks.QueryTask("http://myserverpathName/ArcGIS/rest/services/myService/MapServer/3");         var regionQuery = new esri.tasks.Query;         regionQuery.text = e.options[e.selectedIndex].text;//this is my primary display field  if you needed another field, use a where clause         regionQuery.returnGeometry = true;         regionQueryTask.execute(regionQuery,showRegionResults);     }

The result function of the initial query finds the geometry of the feature that is selected in findRegion

function showRegionResults (results) {         region = results.features[0].geometry;         map.setExtent(region.getExtent(), true);  //zooms to the region         findFeatureInRegion(region);     }  function findFeatureInRegion(region) {    var newQueryTask = new esri.tasks.QueryTask("http://myserverpathName/arcgis/rest/services/myService/MapServer/2"); //EUSstaff    var newQuery = new esri.tasks.Query;    newQuery.outFields = ["*"];    if (region) {    newQuery.geometry = region;    newQuery.spatialRelationship = esri.tasks.Query.SPATIAL_REL_CONTAINS;    newQueryTask.execute(newQuery);  dojo.connect(newQueryTask, "onComplete", function(results){  //whatever you wanted to do with the features that were selected in the 2nd query } }