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https://github.com/RDFLib/rdflib-sqlalchemy
RDFLib store using SQLAlchemy dbapi as back-end
https://github.com/RDFLib/rdflib-sqlalchemy
Last synced: 3 months ago
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RDFLib store using SQLAlchemy dbapi as back-end
- Host: GitHub
- URL: https://github.com/RDFLib/rdflib-sqlalchemy
- Owner: RDFLib
- License: other
- Created: 2012-03-08T02:45:14.000Z (over 12 years ago)
- Default Branch: develop
- Last Pushed: 2024-02-10T23:59:12.000Z (4 months ago)
- Last Synced: 2024-03-17T03:45:59.407Z (3 months ago)
- Language: Python
- Homepage:
- Size: 926 KB
- Stars: 143
- Watchers: 23
- Forks: 33
- Open Issues: 10
-
Metadata Files:
- Readme: README.md
- License: LICENSE.txt
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- alex-mikhalev-awesome-stars - rdflib-sqlalchemy - RDFLib store using SQLAlchemy dbapi as back-end (Python)
README
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. Table names are prefixed `kb_{identifier_hash}`, where `identifier_hash` is the first ten characters of the SHA1 hash of the given identifier.
Back-end persistence
--------------------
Back-end persistence is provided by SQLAlchemy.
Tested dialects are:
- SQLite, using the built-in Python driver
- MySQL, using the MySQLdb-python driver or, for Python 3, mysql-connector
- PostgreSQL, using the psycopg2 driver or the pg8000 driver.
pysqlite: https://pypi.python.org/pypi/pysqlite
MySQLdb-python: https://pypi.python.org/pypi/MySQL-python
mysql-connector: http://dev.mysql.com/doc/connector-python/en/connector-python.html
psycopg2: https://pypi.python.org/pypi/psycopg2
pg8000: https://pypi.python.org/pypi/pg8000
Development
===========
***Note: Currently, rdflib-sqlalchemy is in maintenance mode. That means the
current maintainer (@mwatts15) will do what he can to keep the package working
for existing use-cases, but new features will not be added and newer versions
of SQLAlchemy will not be supported. If you have an interest in further
development of rdflib-sqlalchemy, please get in touch with @mwatts15 or [core
RDFLib project developers][rdflib-contact].***
[rdflib-contact]: https://rdflib.readthedocs.io/en/stable/#further-help-contact
Github repository: https://github.com/RDFLib/rdflib-sqlalchemy
Continuous integration: https://travis-ci.org/RDFLib/rdflib-sqlalchemy/
An illustrative unit test:
==========================
```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):
self.graph = Graph("SQLAlchemy", 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
=================
`pytest` is supported as a test runner, typically called via `tox`. Select the
SQL back-end by setting a `DB` environment variable. Select the database
connection by setting the `DBURI` variable. With `tox`, you can also specify
the Python version.
Using pytest::
DB='pgsql' DBURI='postgresql+psycopg2://user:password@host/dbname' pytest
Using tox::
DB='pgsql' DBURI='postgresql+psycopg2://user:password@host/dbname' tox -e py310
DB variants are 'pgsql', 'mysql' and 'sqlite'. Except in the case of SQLite,
you'll need to create the database independently, before execution of the test.
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:password@hostname:port/database')
dburi = Literal('postgresql+pg8000://user:password@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