How to convert the data in Android DBs to rdf data?

Question

I'm trying to extract rdf data from android DB.

It means that I want to get rdf data from contacts DB, callendar DB, and so on directly.

I know that the current android platform have used SQLite DB.

Is it available to extract rdf data?

Surely, I can make the same data typed of rdf manually.

Here, My converting criterion is that the table name means Subject of rdf, the column name means Predicate, and the value means Object.

But the important issue is how to convert data in the existing data in Android DB to RDF data automatically.

I found that the tools such as AndroJena, uJena, Sesame... don't support that functionality.

Help me plz.

PS)

I searched many posts here and I found that someone had stuggled with the similar problem.

He got the solution like below.

1. First, Copy ur android DB on your own DB in desktop.

2. Second, Nomalize the copied DB.

3. Third, Make rdf triples by utilizing the modified DB.

3.1. By referencing such papers titled as RDB to RDF and following the defined converting rules from those, convert data to the data typed of RDF.

Above solution is the only answer?

Answer 1

The general question of converting from a relational DB to RDF was covered by W3C's RDB2RDF working group. This group finished the standards they produced in 2012.

There are two styles, to just directly map to RDF (Direct Mapping) or to map using mapping rules in R2RML. If you convert directly then you can use all your favorite tools to map into the ontology want.

See the Implementation report for a list of implementations at the time it was written. There may be many other bits of software kicking around the web which do this sort of thing, which have been produced more recently or were not spotted then by the group.

Answer 2

The whole RDB2RDF issue is still very much under development. However, D2RQ precedes this discussion and we found this a useful tool to 'automatically' go from RDB to RDF. This only requires a mapping. The code is all in Java, so it is probably possible to adapt it and deploy it to your android phone.

A few notes: D2RQ is not under development anymore (as far as I know) and you still have to make a mapping on how to translate the relational database to rdf.