Data entry - forms design or other APIs etc. - what is there?

I'm working on an application for my own use and have been using knoda
as a front end to postgresql but I need a bit more power and flexibility.

I'm quite happy to get into relatively serious programming as I am a
C++/Java programmer, this accounting package is rather out of my
normal line of work though.

What methods are available to produce data entry forms for postgresql
databases? If, for example, one wanted to migrate a system that used
Oracle Forms to Postgresql what would one use? This seems to me to be
an area which is not aired much here and that surprises me because a
database is of no use unless one can get data into it.

I'd prefer something that isn't web based but if that's the only way
to go then I do have a web server (apache) on the system where the
Postgresql database is. It doesn't have to be multiuser really either
as I'm probably going to be the only user.

All I want is a way to produce reasonably functional forms for
entering data into a Postgresql database which will allow me to do the
following:-

Show a database table in a 'table view' type format which will
allow deletion, modification and insertion of rows.

Has 'hooks' so that one can have actions which occur on entry to
and exit from certain fields.

Can calculate and preload some fields.

I don't need sophisticated layout facilities, nor do I need
sophisticated reporting as I think knoda can do all I need on that
front.

Any suggestions or ideas would be very welcome.

--
Chris Green (chris(at)areti(dot)co(dot)uk)

"Never ascribe to malice that which can be explained by incompetence."