ppf.jabref provides a python interface to JabRef SQL databases. It maps database relations to python classes using SQLAlchemy. Also, ppf.jabref provides tools to parse the data stored inside the database tables.
A JabRef database has these tables:
- ENTRY holds an ID, the entry type (e.g. 'book', or 'article'), and a version number
- FIELD uses the same entry as a foreign key, and lists all the fields in the entries row by row as key-value pairs.
- METADATA holds data about your library such as the base path of your document folder and the definitions of your filter groups.
The "file" field is a text describing which files are linked the the present entry. Note that all linked files are listed in a single row in the DB. The links are separated by ';' inside the text. Also, each link has multiple properties: name, path, and filetype. In the following example, entry_shared_id 2 has a single link with name='', path='a.pdf', filetype='PDF'.
ppf.jabref relies on SQLAlchemy for database access. All that ppf.jabref adds to this is a data model which makes sqlalchemy understand how a JabRef database is structured (by providing classes Entry and Field).
A simple example that queries all entries and prints a selection of the fields looks like this:
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from ppf.jabref import Entry, File
engine = create_engine('<your connection string here>', echo=False)
Session = sessionmaker(bind=engine)
session = Session()
q = session.query(Entry)
for entry in q:
print(entry.fields['author'], '\t',
entry.fields['title'], '\t',
entry.fields['year'], '\t', end='')
files = File.from_string(entry.fields['file'])
for i in range(len(files)):
f = files[i]
print(f.path, '\t', end='')The first 6 lines are setup code to import required packages and to set up the database connection. The query then uses ppf.jabref's Entry class to obtain all Entries (=references) in the JabRef database. The for-loop shows how to access fields and uses the File class to find out where the documents linked to this entry are stored.