Attribute Query

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Summary: Use this process to run a query on a Feature data source (the Input Features) and return the subset of matching features as a new Feature data source.

Input:

  • Input Features (1 and only 1 Feature Collection) The feature collection to run the query against.

Output: Feature , Feature Collection , Record

  • Description: A new feature collection that only contains features that match the query.

Attributes:

  • geometry Indicates which geometry (input or result) to use.
  • query The query to perform (written in XPath).

Details

To specify the output for the process:

1. In the Pipeline Editor, double-click the name of the Attribute Query process to open the Process Editor dialog box.

2. In the Process Editor dialog box, under Attributes, set the geometry attribute to one of the following:

  • use_input_geometry - This is much faster because it does not have to recalculate a geometry and just passes on the original geometry of the input feature data set. Use this option if the results of this process are just going to be visualized on the screen, as you won’t see a difference in the output.
  • use_result_geometry - This option makes this process have a geometry that is the intersection of all of the features that match the query. This takes more time, but then can be used as the input to other processes like the Mask by Area process to cut out data in the shape of the features that match this query.
  • Note: The default value for the geometry attribute is use_input_geometry.

3. Enter the query in the query attribute.

Note

The query is written in XPath. If you want to play with the query go ahead, and use XPath documentation as your guide. We don’t intend to support editing the XPath query directly in this documentation, as the long term goal is to build a better user interface that will create richer queries without having to know XPath.

Example

If you have a feature data set of the Provincial parks in Canada, and it has a “Hot Showers” field containing “Yes” or “No” values, then you could use this process to show only the parks with hot showers. The resulting data set is usable in all the same places as the input data set since this process has the same input type as output type.

 //field[name='Hot Showers' and value='Yes']
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