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Query a table to get aggregated statistics back for a specific field.

Image of statistical query

Use case

For example, a county boundaries table with population information can be queried to return aggregated results for total, average, maximum, and minimum population, rather than downloading the values for every county and calculating statistics manually.

How to use the sample

Pan and zoom to define the extent for the query. Use the ‘Only cities in current extent’ checkbox to control whether the query only includes features in the visible extent. Use the ‘Only cities greater than 5M’ checkbox to filter the results to only those cities with a population greater than 5 million people. Click ‘Get statistics’ to perform the query. The query will return population-based statistics from the combined results of all features matching the query criteria.

How it works

  1. Create a ServiceFeatureTable with a URL to the feature service.
  2. Create StatisticsQueryParameters, and StatisticDefinition objects, and add to the parameters.
  3. Execute queryStatistics() on the ServiceFeatureTable. Depending on the state of the two checkboxes, additional parameters are set.
  4. Display each StatisticRecord in the first returned QueryStatisticsResult.

Relevant API

  • QueryParameters
  • ServiceFeatureTable
  • StatisticDefinition
  • StatisticRecord
  • StatisticsQueryParameters
  • StatisticsQueryResult
  • StatisticType

Tags

analysis, average, bounding geometry, filter, intersect, maximum, mean, minimum, query, spatial query, standard deviation, statistics, sum, variance

Sample Code

module-info.java module-info.java StatisticalQuerySample.java
/*
* Copyright 2022 Esri.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
module com.esri.samples.statistical_query {
// require ArcGIS Maps SDK for Java module
requires com.esri.arcgisruntime;
// handle SLF4J http://www.slf4j.org/codes.html#StaticLoggerBinder
requires org.slf4j.nop;
// require JavaFX modules that the application uses
requires javafx.graphics;
requires javafx.controls;
exports com.esri.samples.statistical_query;
}