Maybe.. a spreadsheet-like interface to allow the user to design the database.
But that's really hard. :(
Personally I'd like to start by English language parsing of the description because if the parse fails due to ambiguity it means the user does not understand their problem well enough in the first place.
Incidentally deterministic parsing of English is possible and has been so for the last 30 odd years. Search "parsifal" for an example, while a PhD at Edingburgh demonstrated that a 2 word lookahead and evaluation stack was adequate to get the job done.