readme.md

Statistical query group and sort

Query a feature table for statistics, grouping and sorting by different fields.

How to use the sample

Use the buttons to add statistic definitions, define group and order by fields, and execute the query.

How it works

1. Create a ServiceFeatureTable using the URL of a feature service and load the table.
2. Get the feature tables field names list with featureTable.Fields.
3. Create StatisticDefinitions specifying the field to compute statistics on and the StatisticType to compute.
4. Create StatisticsQueryParameters passing in the list of statistic definitions.
5. To have the results grouped by fields, add the field names to the query parameters' GroupByFieldNames collection.
6. To have the results ordered by fields, create OrderBys, specifying the field name and SortOrder. Pass these OrderBys to the parameters' OrderByFields collection.
7. To execute the query, call featureTable.QueryStatisticsAsync(queryParameters).
8. Get the StatisticQueryResult. From this, you can get an iterator of StatisticRecords to loop through and display.

Relevant API

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

About the data

This sample uses a Diabetes, Obesity, and Inactivity by US County feature layer.

Tags

group, result, sort, statistics, stats