[DB-SIG] dBase III and VFP tables

Ethan Furman ethan at stoneleaf.us
Wed Jul 20 01:39:45 CEST 2011


Greetings,

I am finally adding Null support to my dbf package 
(http://pypi.python.org/pypi/dbf) and, as usual, the VFP side is being a 
pain.

The issue is that the Logical, Date, and DateTime field types, even when 
the table does not allow Null values, can be empty -- and when Null 
values are allowed, those fields can be empty or Null.  (Empty pretty 
much meaning not initialized -- neither True nor False, and no Date nor 
Time.)

At this point, also, my module does not support the DB API (that is a 
goal though), so right now you pretty much get direct access to the 
physical table.

My question:  for the direct access side, is there any advantage to 
treating an empty L, D, or T field differently from a Null L, D, or T 
field?  Or should they be semantically the same, always returning, for 
example, None whether it's actually Null in the table or just empty?

~Ethan~


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