topic Re: returnDistinctValues not returning distinct in ArcGIS JavaScript Maps SDK Questions

returnDistinctValues not returning distinct

jamesmuir — Thu, 06 Feb 2014 19:07:44 GMT

I am trying to perform a query to return distinct values from my map service running on 10.1. The returned result has 1000 records (the max set in the server) and when i inspect it I am seeing duplicate values. Here is my code.

var queryTask = new esri.tasks.QueryTask(layerServiceUrl);             var query = new esri.tasks.Query();             query.where = "1=1";             query.outFields = [];             query.outFields.push(field);             query.returnDistinctValues = true;

Can someone tell me what I am doing wrong?

Re: returnDistinctValues not returning distinct

KenBuja — Thu, 06 Feb 2014 19:43:28 GMT

That is not a property of Query yet. Take a look at this thread.

Re: returnDistinctValues not returning distinct

jamesmuir — Mon, 10 Feb 2014 12:30:35 GMT

Unfortunately, you are correct. Thank you.

Re: returnDistinctValues not returning distinct

KenDoman — Fri, 22 Aug 2014 14:21:11 GMT

For a temporary hack until the Query property supports the feature, try tacking it into your QueryTask url definition. It may not work in all cases.

example: var qtask = new QueryTask(url + "?returnDistinctValues=true");

Re: returnDistinctValues not returning distinct

RobertScheitlin__GISP — Fri, 22 Aug 2014 14:28:21 GMT

All,

This has been brought back to the attention of the JavaScript API team for inclusion in the next release:

See this thread:

returnDistinctValues‌

Re: returnDistinctValues not returning distinct

KenDoman — Tue, 02 Sep 2014 20:46:35 GMT

As a side note, this hack doesn't work if you're using QueryTask.executeForCount. There's probably other places it doesn't work. We anxiously await the next release.

Re: returnDistinctValues not returning distinct

Anonymous User — Tue, 02 Sep 2014 22:17:26 GMT

Yes, implementing this is under consideration. In the mean time, it is possible to do with the current release of the JavaScript API (but without a nice and clean name like returnDistinctValues). The solution is to add the "esri/tasks/StatisticDefinition" module to your project. Then do the following:

1) Set the statistics type to "count" (see doc, statisticdefinition-amd | API Reference | ArcGIS API for JavaScript)

2) Set groupByFeildsForStatistics to the field of interest (see doc, query-amd | API Reference | ArcGIS API for JavaScript )

The result will be a short list of distinct values with respective feature counts. Hope this helps.

-Doug

PS or go with what Kelly suggests in the post Robert refers too.