Tutorial: Query a feature layer (spatial)

Import modules and log in

1. Import the arcgis.gis module.

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   from arcgis.gis import GIS
   
   
   

2. Log in anonymously to ArcGIS Online to access publicly shared data. Since this dataset is public you do not need credentials to access it. If it were a private dataset, you would be required to log in

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   from arcgis.gis import GIS
   
   
   portal = GIS()
   
   

Access the feature layer

1. Use the ContentManager class to access the dataset by Item ID.

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   portal = GIS()
   
   parcel_layer_item = portal.content.get("a6fdf2ee0e454393a53ba32b9838b303")
   
   parcel_layer = parcel_layer_item.layers[0]
   
   

Run the query

1. Create an Extent object as a geometry filter. The contains method will return only the features that are wholly contained within this extent. The as_df parameter is set to False so that the results will be returned as FeatureSet. Set the out_fields as an array of field names to be included in the results.
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   parcel_layer_item = portal.content.get("a6fdf2ee0e454393a53ba32b9838b303")
   
   parcel_layer = parcel_layer_item.layers[0]
   
   from arcgis.geometry.filters import contains
   
   query_extent = {
       "xmin": -13198303.18,
       "ymin": 4059062.83,
       "xmax": -13197797.98,
       "ymax": 4059421.13,
       "spatialReference": {"wkid": 102100},
   }
   
   query_filter = contains(query_extent, sr=102100)
   
   results = parcel_layer.query(
       geometry_filter=query_filter, out_fields="APN, UseType", as_df=False
   )
   results
   
   
   

Display the results

1. Use the map method to create a map widget. Use the add_layer() method to add the results FeatureSet to the map and the zoom_to_layer() method to set the maps extent so the query results are visible.

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   from arcgis.geometry.filters import contains
   
   query_extent = {
       "xmin": -13198303.18,
       "ymin": 4059062.83,
       "xmax": -13197797.98,
       "ymax": 4059421.13,
       "spatialReference": {"wkid": 102100},
   }
   
   query_filter = contains(query_extent, sr=102100)
   
   results = parcel_layer.query(
       geometry_filter=query_filter, out_fields="APN, UseType", as_df=False
   )
   results
   
   
   map = portal.map()
   map
   
   map.add_layer(results)
   map.zoom_to_layer(results)
   
   

2. Optional: Use the export_to_html method to export the current state of the map widget to a static HTML file which can be viewed in any web browser.

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   map = portal.map()
   map
   
   map.add_layer(results)
   map.zoom_to_layer(results)
   
   import os
   
   file_path = os.path.join(os.getcwd(), "home", "query-a-feature-layer-sql.html")
   
   map.export_to_html(file_path, title="Query a feature layer (SQL)")

When the map displays, the features returned from the query are displayed in the center of the map. Click on a parcel to show a pop-up with the features attributes.