FreeTDS Development Group

["James K. Lowden" <jklowden AT schemamania.org>]

On Mon, 05 Jan 2004, Steven Orton <sorton9999 AT usa.net> wrote:
> 
>   oh man....that is unfortunate :(  it would make my life a hell of a
>   lot
> easier if i could get a multirow resultset and basically search through
> the same set multiple times.  so basically, if i want to search through
> the set again, i have to dump the old and get a new?  i guess that's why
> the big boys are getting buku $$$$$, ehhh?

At the risk of making a virtue of necessity, can I offer some advice? 
You're not so bad off as you think.  

Database libraries include a lot of fanciness passed off as features, and
in fact to someone writing applications in C they must look pretty nice. 
To someone writing applications in C, I guess flint and steel look pretty
advanced.  

But you're using C++, which means you have STL, which is a far far better
thing than any ODBC cursor feature.  You have to iterate over the result
set anyway, so why not store your rows as a std::set?  Then you can pick
them out any way you like.  

I never really learned how to program cursors and "for browse" operations.
 In 10 years, I guess I've opened three cursors.  Everytime I'm tempted, I
get bogged down in the unhealthy details, and find that a T-SQL loop or
STL container is really the better answer.  

Define a class for your row, override operator[]() and operator<(), and
live longer.  You and your code will be happier and better looking.  

--jkl

> "Lowden, James K" <LowdenJK AT bernstein.com> wrote:
> 
> > > From: Steven Orton [mailto:sorton9999 AT usa.net]
> > > Sent: January 5, 2004 4:55 PM
> > > 
> > >   I have a technical question that pertains to random access 
> > > of the rows in a multirow resultset.  
> > >   First of all I am using freeTDS-0.62.dev.20031218 with the 
> > > 0.2.3 version of
> > > ODBC++ (freeodbc) and using TDSVER=7.0 on a RH9.0 client getting at
> > > a SQLServer 7.0 DB. 
> > ..
> > >   My question is, Can one create a random access multirow 
> > > resultset using the
> > > TDS API.  
> > 
> > I don't think it is.  You seem to have pointed up a bug in our
> > documentation: our api_status.txt file (and new User Guide) indicates
> > SQLFetchScroll is "OK", but the source code disagrees:
> > 
> > SQLRETURN SQL_API
> > SQLFetchScroll(SQLHSTMT hstmt, SQLSMALLINT FetchOrientation,
> > SQLINTEGER FetchOffset)
> > {
> >         INIT_HSTMT;
> > 
> >         /* still we do not support cursors and scrolling */
> >         if (FetchOrientation != SQL_FETCH_NEXT) {
> >                 odbc_errs_add(&stmt->errs, "HY106", NULL, NULL);
> >                 ODBC_RETURN(stmt, SQL_ERROR);
> >         }
> > 
> >         ODBC_RETURN(stmt, _SQLFetch(stmt));
> > }
> > 
> > In this case, I'd believe the source code.  :-(
> > 
> > You don't get a "HY106" error somewhere along the line?  
> > 
> > > If that IS possible, I can try to update my ODBC++ 
> > > library (since I
> > > think this is a unsupported library at present).
> > 
> > Only because no one's stepped up to it.  There seem to be a few people
> > interested in ODBC++; all that remains is for a knowledgeable someone
> > to write up how to hook it up to FreeTDS.  
> > 
> > --jkl