>If I want to develop for all these database engines: SQLServer, MySQL, PostgreSQL which are the common data types that I should select in order to have single VFP codebase?
>
>For logical values, for money, for text?

Sorry for tackling your thought process from sideways, but if you want to have a vfp codebase,
I'd code in the best way vfp offers with all those data types available in vfp
and worry about the backends exactly when each backend is asked for.

Delegate such questions to your data access layer:
Map the best type of each backend into the vfp column via a special cursoradapter classes.
It is very doubtful that besides logical values sometimes done via 1/0 numerical or bit types
the backend will have less options than the dated vfp - if so, create a special char field
and corresponding transformation methods.

multi-backend SP dev is not possible with this, but IMHO also not really an option:
you use SP to get the benefit of backend specialities (beisides other benefits).

regards

thomas