SQL RDF MAPPER
converts SQL Data into RDF Data
Semweb provides its own developped SQL RDF Mapper to convert table data into RDF Data.
The mapper was used to build RDF data for glamrdfdata_online and glamsearchportal.
For each table in a database, it displays table schama with information on keys and permits the definition of one or several maps using TURTLE expressions, which are evaluated inside a sesame RDF model.
A single tenant online version will be available for the duration of the hackaton under the link https://ch.semweb.ch:8151/SQLRDFSTAR/GUI.jsp
Note : This mapper is freely available until July 31 2016. From July 25 2016 on, a similar but much more secure service will be available upon https://rdflink.ch
"User manual"\ The user selects one table and press the orange button to create a first blank TURTLE MAPPING SCHEMA. Once the TURTLE SCHEMA appears, the user can define a mapping for the key of the record and several mappings for each of the table columns. Inside each mapping several functions can be used:
- Explosion of a single column value by means of a separator (e.g. "one,two,three" exploded by ",")\
- Extraction of regular expressions out of values\
- If-Then expression (do map, donot map)\
- Table lookp in other table while mapping
Inside a TURTLE Mapping several maps can be defined, one for each SPARQL Endpoint. For instance if you wish to scan a table and map one RDF code to one RDF Store and another RDF code (might be different) to another RDF Store, then you define two mappings.\ Testing a Mapping\ Before you execute a map you should validate the TURTLE syntax and after successful validation you should store that mapping and make a version.
Then you can test a validated map on 1 or 2 records using the verbose option, click on one generated link and see what has been mapped.
another way to test a map is to define from-which records you would like to test, then to start the online tool by licking on the table symbol on the left of a table record. This online tool permits you to see the table records together with the mapped triples, as pictures 2 and 3 show.
Important: Use this mapper one at a time, since it is not (yet) multi-tenant.
Picture 2: Online Tool showing a map of a table - triples above, records below
Picture 3: Online Tool showing the same map of a table - triples above, transposed records below
Picture 4: Execution dialog (before start)
Picture 5: Execution results
MAPPER FUNCTIONS
Picture 6: Mapper explode function (German)
Picture 7: Mapper regex function
Picture 8: Mapper table lookup function
Picture 9: Mapper if-then function
Data
Data for this tool are SQL tables.
Date must be uploaded into the table.
If you do not find an upload mechanism on the main page, please ask me (Fabio Ricci) to upload your table data.