It should be possible to implement a subclass of DataPatternAttribute or
DataAttribute that loads data from a database or Excel spreadsheet.
It shouldn't be too hard, actually.
You could perhaps throw something together based on RowAttribute.cs using
OleDbDataAdapter or maybe a third party .Net library for reading Excel
Don't dismiss [CsvData] out of hand though. It's pretty powerful. CSV
spreadsheets can be loaded into Excel just like ordinary worksheets.