Reusable Parameterized Queries in AGS

Kedar

Parameterized Template Query

🧩 All examples on this page use the sample movie dataset introduced in SPARQL in AGS – Developer’s Overview

Reusable parameterized templates make logical filters configurable without modifying query logic.
This is the preferred approach for Named Queries and automated workflows in AGS.

PREFIX ex: <http://example.org/movie/>


SELECT ?title ?genre

WHERE {

  ?m a ex:Movie ;

     ex:title ?title ;

     ex:genre ?genre .


  # The include list is passed at runtime

  VALUES ?genre { ${includeGenres} }


  # The exclude condition is parameterized as well

  FILTER NOT EXISTS { ?m ex:genre ${excludeGenre} }

}

ORDER BY ?title

Template Parameters

Parameter	Example Value	Description
${includeGenres}	"Drama" "Crime"	Genres to include
${excludeGenre}	"Action"	Genre to exclude

Runtime Expansion (Executed Query Example)

At runtime, AGS automatically substitutes the parameter placeholders with actual values:

PREFIX ex: <http://example.org/movie/>


SELECT ?title ?genre

WHERE {

  ?m a ex:Movie ;

     ex:title ?title ;

     ex:genre ?genre .


  VALUES ?genre { "Drama" "Crime" }

  FILTER NOT EXISTS { ?m ex:genre "Action" }

}

ORDER BY ?title

Result

Title	Genre
The Shawshank Redemption	Drama
The Godfather	Crime
Pulp Fiction	Crime

How to use:

• Replace hardcoded lists with parameter placeholders like ${includeList} and ${excludeList}.
• When used in AGS Named Queries or Templated Steps, parameters are passed dynamically, ensuring reusability and maintainability.

Reusable Pattern Principle:

Parameterized templates allow you to define query logic once and execute it many times with different inputs.
They separate logic definition from runtime execution for better maintainability and governance.

• Parameters Query: produces lists or sets (e.g., genres to include/exclude)
• Template Query: consumes those lists dynamically using SPARQL variables or parameters (e.g., ${includeGenres})

This allows one query template to handle many conditions simply by changing the parameters.

Learn More at: Create a Query-Driven Template

Integration in Real Projects (Developers’ View)

Principle	Implementation in AGS
Parameterization	Use Query Variables (${includeGenres}) for input lists
Templates	One SPARQL template handles multiple use cases
Security	Pass parameters via Query Context Variables — no hardcoding
Scalability	Extend lists without changing logic
Maintainability	Keep logic centralized; update lists dynamically