RDFLib-SQLAlchemy

A SQLAlchemy-backed, formula-aware RDFLib Store. It stores its triples in the following partitions:

• Asserted non rdf:type statements
• Asserted rdf:type statements (in a table which models Class membership) The motivation for this partition is primarily query speed and scalability as most graphs will always have more rdf:type statements than others
• All Quoted statements

In addition, it persists namespace mappings in a separate table.

Development

Github repository: https://github.com/RDFLib/rdflib-sqlalchemy

Travis-CI build status:

An illustrative unit test:

.. code-block:: python

import unittest
from rdflib import plugin, Graph, Literal, URIRef
from rdflib.store import Store


class SQLASQLiteGraphTestCase(unittest.TestCase):
    ident = URIRef("rdflib_test")
    uri = Literal("sqlite://")

    def setUp(self):
        store = plugin.get("SQLAlchemy", Store)(identifier=self.ident)
        self.graph = Graph(store, identifier=self.ident)
        self.graph.open(self.uri, create=True)

    def tearDown(self):
        self.graph.destroy(self.uri)
        try:
            self.graph.close()
        except:
            pass

    def test01(self):
        self.assert_(self.graph is not None)
        print(self.graph)

if __name__ == '__main__':
    unittest.main()

Running the tests

This is slightly baroque because of the test matrix (PostgreSQL|MySQL|SQLite x Python2.5|2.6|2.7|3.2) ...

Using nose::

DB='pgsql' DBURI='postgresql+psycopg2://user:password@host/dbname' nosetests

Using tox::

DB='pgsql' DBURI='postgresql+psycopg2://user:password@host/dbname' tox -e py32

DB variants are 'pgsql', 'mysql' and 'sqlite'

Sample DBURI values::

dburi = Literal("mysql://username:password@hostname:port/database-name?other-parameter")
dburi = Literal("mysql+mysqldb://user:password@hostname:port/database?charset=utf8")
dburi = Literal('postgresql+psycopg2://user:pasword@hostname:port/database')
dburi = Literal('sqlite:////absolute/path/to/foo.db')
dburi = Literal("sqlite:///%(here)s/development.sqlite" % {"here": os.getcwd()})
dburi = Literal('sqlite://') # In-memory