nisavid/pyrdb2rdf

A Python library for RDB2RDF Direct Mapping and R2RML.

pyrdb2rdf's Issues

How does the library work?

import rdflib as _rdf
import sqlalchemy as _sqla

db_str = 'postgresql://testuser:testpasswd@localhost/testdb'
db = _sqla.create_engine(db_str)
graph = _rdf.Graph('rdb2rdf_dm')
graph.open(db)

print(graph.serialize(format='nt'))

How does this code work?

quote is no longer a part of base urllib but urllib.parse

Running:
graph = _rdf.Graph('rdb2rdf_dm')
results in

ImportError: cannot import name 'quote' from 'urllib' (C:\ProgramData\Anaconda3\lib\urllib_init_.py)

Possible solution:
update _common.py
from
from urllib import quote as _pct_encoded
to
from urllib.parse import quote as _pct_encoded

Using rdf2rdf with existing databases raises exception

Trying to use rdb2rdf with an existing database I get:

sqlalchemy.exc.ArgumentError: WARNING: when configuring property 'value' on 
Mapper|value_data|value_data, column 'value' conflicts with property '<RelationshipProperty at 
0x4be1710; value>'. To resolve this, map the column to the class under a different name in the 
'properties' dictionary.  Or, to remove all awareness of the column entirely (including its availability as a 
foreign key), use the 'include_properties' or 'exclude_properties' mapper arguments to control 
specifically which table columns get mapped.