Re: [boost] Interest in an ODBC library?

From: Jonathan Wakely (cow_at_[hidden])
Date: 2005-08-18 09:59:57

Brock Peabody wrote:

> > On Behalf Of Jonathan Wakely
> > I have an implementation of your database library for MySQL.  It's on
> my
> > hard drive at home and I'm broadband-less right now so if anyone wants
> > to see it let me know and I'll dial up tonight.  It was very easy to
> > adapt to use the MySQL API.
> 
> I'd like to see it when you get a chance.

Sure, I'll post it tonight or tomorrow.

> > postgresql/connect.cpp accidentally uses the <:: trigraph in the
> > typedefs at the top of the file.  You need a space before the template
> > args to avoid that.
> 
> Maybe I should put the files in the sandbox?  Did you happen to make
> Boost.Jam files to compile the test?

No, I'm fairly proficient with make and completely ignorant of bjam
so I knocked up a Makefile that would let me test your impl and
mine with either "make IMPL=postgresql" or "make IMPL=mysql" (and is
easily extended to other impl's).

> > How do you handle NULL values?  the postgresql::row_set_imp::get()
> > function
> > doesn't seem to account for NULL, which would crash strlen(), atof()
> etc.
> 
> I was thinking about this some more.  Long ago, where I work we had bad
> experiences with once working programs crashing when they tried to read
> null fields (via DAO) when we really just wanted default values (0s and
> empty strings).  Ever since then when I've written a wrapper for a
> database library I've always provided automatic conversion of nulls to
> default values.
> 
> Now that you've brought this up, however, I can see that not only are
> nulls important to some users, but that they will also be important for
> the serialization library when serializing boost::optionals.  The method
> I'm using now is not so good.

Yes, it's essential to distinguish NULL in some situations (particularly
if you've got left joins in the query)

jon

--
"Some men are born mediocre, some men achieve mediocrity,
 and some men have mediocrity thrust upon them."
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