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EXPRESS-Q

Overview

EXPRESS-Q is a query language for interrogating and retrieving data from EXPRESS-defined datasets. It provides a declarative syntax for defining views, queries, and business objects over EXPRESS schema data, enabling efficient data retrieval and reporting.

EXPRESS-Q complements the other EXPRESS languages by providing a way to extract and present information from EXPRESS datasets without modifying the underlying schemas.

Key features

  • VIEW_ENTITY declarations — define virtual entities as projections over source data

  • QUERY_FUNCTION definitions — reusable parameterized queries

  • Business objects — define domain-specific views over technical EXPRESS data

  • Data retrieval — efficient extraction of subsets from large EXPRESS datasets

  • Report generation — structured output of queried data

Syntax

EXPRESS-Q uses declarative query constructs integrated with EXPRESS type definitions:

Example EXPRESS-Q view entity
VIEW_ENTITY fastener_summary
  FROM fastener;
  .identifier := source.part_number;
  .diameter := source.diameter;
  .material := source.material.name;
WHERE
  source.diameter > 5.0;
END_VIEW_ENTITY;

History

EXPRESS-Q was developed alongside EXPRESS-X as part of ISO 10303-14, recognizing that schema mapping and querying are complementary operations in the EXPRESS data management lifecycle.

Timeline

2001

EXPRESS-Q published as part of ISO 10303-14 alongside EXPRESS-X

Present

Supported by commercial and open-source EXPRESS tooling

Key people

EXPRESS-Q was developed by the ISO TC 184/SC 4 community, building on the EXPRESS and EXPRESS-X foundation established by Peter Wilson and Douglas Schenck.

Standardization

EXPRESS-Q is defined within ISO 10303-14:

  • ISO 10303-14 — EXPRESS-X: Includes EXPRESS-Q query language definitions

Applications

  • Data reporting — generating summary views from EXPRESS datasets

  • Business intelligence — defining domain-specific views over technical data

  • Data validation — querying datasets for compliance checking

  • Supply chain visibility — extracting status information from product data

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