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
- Create a
ServiceFeatureTable
using the URL of a feature service. - Create a
QueryParameters
with a where clause specified using theWhereClause
property. - Perform the query using
QueryFeaturesAsync(query)
on the service feature table. - 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
search, query
Sample Code
<UserControl
x:Class="ArcGISRuntime.UWP.Samples.FeatureLayerQuery.FeatureLayerQuery"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:esriUI="using:Esri.ArcGISRuntime.UI.Controls">
<Grid>
<esriUI:MapView x:Name="MyMapView" />
<Border Style="{StaticResource BorderStyle}">
<StackPanel>
<TextBlock Text="Enter a state name and press 🔎 to search."
TextAlignment="Center" FontWeight="SemiBold"
IsColorFontEnabled="False"
Margin="0,0,0,5" />
<AutoSuggestBox Text="New York"
QueryIcon="Find"
HorizontalAlignment="Stretch"
QuerySubmitted="QueryEntry_QuerySubmitted" />
</StackPanel>
</Border>
</Grid>
</UserControl>