October 14, 2010
The free-form nature of triple-stores offers a lot of flexibility for constructing databases, but that freedom can also make it less obvious how to find arbitrary data for retrieval, error-checking, or general browsing. Gruff is a freely available graphical triple-store browser that attempts to make data retrieval more pleasant and powerful with a variety of tools for laying out cyclical graphs, displaying tables of properties, managing queries, and building queries as visual diagrams.
Gruff’s new Graphical Query View allows creating queries as diagrams of nodes and links. A query diagram can include actual objects from the store, which you select as in other views, while other nodes and links represent query variables. Group graph patterns such as UNION and OPTIONAL groups can be laid out as grouper boxes that can be nested to any level, with proper nesting maintained automatically.
Once you’ve created a query diagram, Gruff will generate either SPARQL or Prolog code for the query. Seeing the generated query text can help you learn to write SPARQL or Prolog queries better. You can also edit the generated text before performing the query. You can save queries either as graphical diagrams or as actual query text, and load them any time later for modification into related queries. You can even generate a visual graph from query results, showing the network of all triples that are comprised of nodes and predicates that are in the query results and the query itself.
View a recording of the event here – 32 min.
Download the presentation slides here