Scripter and relational databases
You can use Scribus scripting to populate documents with content from a database.
There are no specialities with using databases in the Scribus Scripter. You could use DB as in normal standalone script or application.
PEP-0249 - Python database API v.2.
There are various modules for database access. Remember that the module must be installed in/with the Python version which is used/compiled in Scribus!
I've tested personaly with 100% success: DCOracle2 and MySQL
For standard use cases one may try SQLite (Python DBDriver, About SQLite), a self-contained, serverless, zero-configuration, transactional SQL database engine. It may simplify your script development.
There is an common database example since 1.2.2 and 1.3cvs versions - see. SCRIBUSROOT/share/scribus/samples/sample_db_usage.py docstring (e.g. via Script/About Script... menu) or script content.
You'll need to set right connection parameters in the script file.