Building on previous blog posts, the author shows how to query and combine data from two different datasets. Although the datasets were published by the same organization, they are in two different file formats (CSV and shape). The two datasets are, however, implicitly linked via a key. By converting both datasets into a common data language (RDF), those implicit links can be made explicit, allowing the user to easily query both datasets together.
Keywords: SPARQL, Linked Open Data (LOD), Government Open Data
Author: Goodwin, John
Date created: 2013-08-05 04:00:00.000
Time required: P20M
Educational use: instruction
- Reads and understands high-level descriptions of the classes and properties of a dataset in order to write queries.
- Uses available tools, servers, and endpoints to issue queries against a dataset.
- Uses UNION to formulate queries with multiple possible graph patterns.
- Uses variables in SELECT and WHERE clauses to yield a table of results.