Re: Representing Empty DATE values as NULL

Hello Avery,
"Avery Payne" <apayne@pcfruit.com> wrote:

AP> I'm sorry that I haven't written in awhile with my findings.  I
AP> have completed the FoxPro->ODBC->Access test and the Access ODBC
AP> driver returns a NULL for empty dates.  I've also read up a bit
AP> more on ODBC and have figured out the following:
AP>
AP> 1. ODBC doesn't really support the idea of an empty date.  There
AP> just isn't a representation for it.  However...
AP> 2. ODBC does support returning NULL values, so...
AP> 3. Empty dates represented as NULL will have to be an adequate
AP> solution to the issue.  This means...
AP> 4. ODBC sending data from client->odbc->server with empty dates
AP> translating as NULL should be acceptable, maybe even for the
AP> majority of cases, and
AP> 5. ODBC sending data from server->odbc->client with NULL as a date
AP> is the only real representation that can be afforded to any client.
AP>
AP> The option to pass "empty dates" as NULLs in client->odbc->server
AP> might be one you wish to make available on a permanent basis; or
AP> better yet, just quietly perform the translation in all cases as a
AP> default behavior.  Any comments or suggestions about making it
AP> permanent?  Will it mess something up elsewhere?

Excuse my interrupting, I also have no idea what an empty date is. IFAIK,
such a concept neither exists in ODBC nor in Access.  What is it?

In my experience, Access can do with NULL quite fine and the Access ODBC
driver too.
--
Sincerely,
Dmitriy Ivanov
Common Lisp ODBC interface - lisp.ystok.ru/ysql.html