How to Search with an Ontology Service
The Geoportal extension 9.3.1 provides a reference implementation of an Ontology Service. An ontology service is a way to associate terms with a specific technical meaning that can be unique to your organization. The Geoportal does not include tools to develop an ontology service, but does provide a simple web application based on the GEMET thesaurus as a sample that can be integrated wtih the Geoportal extension. This web application requires a keyword as an input and produces a Lucene query as an output. For more information or updates on the GEMET thesaurus, please see http://www.eionet.europa.eu/gemet/about.
To use a configured ontology service in the Geoportal, follow the steps below.
- Launch the Geoportal
- Click on the Search tab
- Type the name of the ontology service in the search blank (by default, this service will be titled "like"), then a pipe character, and then the term you want to search for in the ontology service
- Click the Search button
- The Geoportal will reference the ontology service to not only find records that contain the search term, but also records with the terms associated with that search term through the ontology service. For example, searching for 'river' not only returns records with the word 'river' but also 'delta', 'estuary', 'waterfall', and more.
- The Geoportal transforms the search term into a Lucene syntax query. This means that all the rules of the lucene syntax search apply. If you want to query field names for a term, such as "title" or "abstract", you can change the query like so:
Here, the term 'river' will be processed by the ontology service named "like", and then the outcome lucene syntax query will be applied to only the field "title".
If you are using Directed Search to search other catalogs from the Geoportal, the ontology service cannot be used for searching those catalogs. In that case, no results will be returned if the "like:term" syntax is used.