Parameterized Queries

Parameterized queries - queries with placeholders that prompt for values at execution time.

Parameterized queries use placeholder variables that GeoDin prompts for when the query runs. They let one query template serve many specific filters (e.g. "find objects in project ?ProjectID with depth > ?MinDepth").

Parameters are defined in the Query Builder with a name, type, and optional default value. At runtime, GeoDin shows a dialog listing each parameter and capturing the user's input before executing the query.

Using result fields for Shape export

The Result fields (Export) node in the query wizard determines which data fields are included in the attribute table when the query result is exported as a Shape file.

To enable Shape export of measurement values (e.g. chloride concentrations):

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Step 1: Open the display fields step

In the query wizard, go to the Set display fields step.

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Step 2: Add the parameter fields

Drag the desired parameter fields (e.g. GWC.CHLORIDE) onto the Result fields (Export) node.

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Step 3: Save the query

Save the query. In the Maps module, the query layer will now expose these fields for labelling, interpolation, and Shape export.

Without result fields, the Shape export contains only geometry and the object ID. Adding measurement parameters here is the prerequisite for generating interpolation maps or contour layers from query results.

Queries on the Measurement Points branch work the same way - result fields defined there are exported alongside the measurement point geometry.

For the comprehensive reference - full syntax, all options, edge cases - see Creating Queries (long-form) and Query Builder Reference.