Feature layer query

Find features in a feature table which match an SQL query.

Use case

Query expressions can be used in ArcGIS to select a subset of features from a feature table. This is most useful in large or complicated data sets. A possible use case might be on a feature table marking the location of street furniture through a city. A user may wish to query by a TYPE column to return "benches". In this sample, we query a U.S. state by STATE_NAME from a feature table containing all U.S. states.

How to use the sample

Input the name of a U.S. state into the text field. When you click the button, a query is performed and the matching features are highlighted or an error is returned.

How it works

1. Create a ServiceFeatureTable using the URL of a feature service.
2. Create a QueryParameters with a where clause specified using the WhereClause property.
3. Perform the query using QueryFeaturesAsync(query) on the service feature table.
4. When complete, the query will return a FeatureQueryResult which can be iterated over to get the matching features.

Relevant API

• FeatureLayer
• FeatureQueryResult
• QueryParameters
• ServiceFeatureTable

About the data

This sample uses U.S. State polygon features from the USA 2016 Daytime Population feature service.

Tags

query, search

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<UserControl x:Class="ArcGISRuntime.WPF.Samples.FeatureLayerQuery.FeatureLayerQuery"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:esri="http://schemas.esri.com/arcgis/runtime/2013">
    <Grid>
        <esri:MapView x:Name="MyMapView" />
        <Border Style="{StaticResource BorderStyle}">
            <StackPanel Orientation="Vertical">
                <TextBlock FontWeight="SemiBold"
                           Text="Enter a state name and click 'Query' to search."
                           TextAlignment="Center"
                           TextWrapping="Wrap" />
                <TextBox x:Name="QueryEntry"
                         Margin="0,5,0,0"
                         Text="New York"
                         TextAlignment="Center" />
                <Button Margin="0,5,0,0"
                        Click="OnQueryClicked"
                        Content="Query" />
            </StackPanel>
        </Border>
    </Grid>
</UserControl>