MIME-Version: 1.0
References: 
 <CA+FnnTx+VJi6o9Y8HHUxb89REdNOxBtz1AVkbvM=TGMF_xa=oA@mail.gmail.com>
 <CADK3HHJLCxp+5Q48CatYqg02hBJs0qs8DS=x=Pg5Nx64rD1F7g@mail.gmail.com>
 <CA+FnnTwB1GJX-ZnO+oAJw+z+rmDVcfK7Huprj7oOj3V88Y2ZUA@mail.gmail.com>
 <CA+FnnTxF+VThVXgobZtu6-jfCc6zfqh1tC4dPtWegfov2CFW3w@mail.gmail.com>
In-Reply-To: 
 <CA+FnnTxF+VThVXgobZtu6-jfCc6zfqh1tC4dPtWegfov2CFW3w@mail.gmail.com>
From: Igor Korot <ikorot01@gmail.com>
Date: Sat, 7 Mar 2026 17:21:37 -0600
Message-ID: 
 <CA+FnnTwzf-UAMs+4i7K=9K=jwr+NzsEYC8ND98uWnngSS8506A@mail.gmail.com>
Subject: Re: How to properly perform this?
To: Dave Cramer <davecramer@postgres.rocks>
Cc: PostgreSQL ODBC list <pgsql-odbc@postgresql.org>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Archived-At: 
 <https://www.postgresql.org/message-id/CA%2BFnnTwzf-UAMs%2B4i7K%3D9K%3Djwr%2BNzsEYC8ND98uWnngSS8506A%40mail.gmail.com>
Precedence: bulk

Dave,

On Sat, Mar 7, 2026 at 5:14=E2=80=AFPM Igor Korot <ikorot01@gmail.com> wrot=
e:
>
> Dave,
>
> This is from the gdb session:
>
> Hi, David,
>
> On Sat, Mar 7, 2026 at 1:06=E2=80=AFPM Igor Korot <ikorot01@gmail.com> wr=
ote:
> >
> > Hi, Dave,
> > I think its just an empty column.
> >
> > Is there a way to treat it as NULL?
> >
> > P.S.: Sorry for top-posting.
> >
> > On Sat, Mar 7, 2026 at 5:41=E2=80=AFAM Dave Cramer <davecramer@postgres=
.rocks> wrote:
> > >
> > >
> > > Dave Cramer
> > > www.postgres.rocks
> > >
> > >
> > > On Sat, 7 Mar 2026 at 01:10, Igor Korot <ikorot01@gmail.com> wrote:
> > >>
> > >> Hi, ALL,
> > >> I'm trying to execute following query:
> > >>
> > >> draft=3D# SELECT c.relname AS name, ixs.tablespace, ARRAY(SELECT
> > >> a.attname FROM pg_attribute a WHERE a.attrelid =3D idx.indrelid AND
> > >> a.attnum =3D ANY(idx.indkey) AND a.attnum > 0 ORDER BY
> > >> array_position(idx.indkey, a.attnum) OFFSET idx.indnkeyatts) AS
> > >> included, c.reloptions AS storage FROM pg_index idx, pg_class c,
> > >> pg_namespace n, pg_class t, pg_indexes ixs WHERE ixs.indexname =3D
> > >> c.relname AND c.oid =3D idx.indexrelid AND t.oid =3D idx.indrelid AN=
D
> > >> n.oid =3D c.relnamespace AND idx.indisprimary AND n.nspname =3D 'pub=
lic'
> > >> AND t.relname =3D 'leagues';
> > >>      name     | tablespace | included | storage
> > >> --------------+------------+----------+---------
> > >>  leagues_pkey |            | {}       |
> > >> (1 row)
> > >>
> > >>
> > >> My code is as follows:
> > >>
> > >>             while( ( ret =3D SQLGetData( m_hstmt, 4, SQL_C_WCHAR,
> > >> index_param.get(), 255, &ind[3] ) ) !=3D SQL_NO_DATA )
> > >>             {
> > >>                 if( ret =3D=3D SQL_SUCCESS || ret =3D=3D SQL_SUCCESS=
_WITH_INFO )
> > >>                 {
> > >>                     auto numBytes =3D ind[3];
> > >>                     if( ind[3] =3D=3D SQL_NO_TOTAL )
> > >>                         numBytes =3D 255;
> > >>                     else if( ind[3] > 255 )
> > >>                         numBytes =3D 255;
> > >>                     str_to_uc_cpy( options, index_param.get() );
> > >>                 }
> > >>                 else
> > >>                 {
> > >>                     GetErrorMessage( errorMsg, STMT_ERROR  );
> > >>                     result =3D 1;
> > >>                 }
> > >>             }
> > >> Unfortunately it goes into the loop because apparently the driver or
> > >> the server keeps seeing the last column as having data and returns
> > >> SQL_SUCCESS.
> > >>
> > >> What is the proper way to resolve this?
> > >>
> > >> I'm using unixODBC with PostgreSQL 16.
> > >>
> > >> My odbc.ini looks like this:
> > >>
> > >> [code]
> > >> [postgres]
> > >> Driver=3DPostgres
> > >> Description=3DPostgres ODBC Driver
> > >> UserId=3Dpostgres
> > >> Password=3DXXX
> > >> Servername=3Dlocalhost
> > >> Database=3Ddraft
> > >> Port=3D5432
> > >>
> > >> [/code]
> > >>
> > >>
> > >> What is the best way to proceed?
> > >
> > >
> > > is the last column empty or null?
> > >
> > > if not null then there is data there.
>
>  3754                while( ( ret =3D SQLGetData( m_hstmt, 3,
> SQL_C_WCHAR, included.get(), 255, &ind[2] ) ) !=3D SQL_NO_DATA )
> (gdb) n
> 3756                    if( ret =3D=3D SQL_SUCCESS || ret =3D=3D SQL_SUCC=
ESS_WITH_INFO )
> (gdb) p ind[2]
> $1 =3D 4
> (gdb) n
> 3758                        auto numBytes =3D ind[2];
> (gdb)
> 3759                        if( ind[2] =3D=3D SQL_NO_TOTAL )
> (gdb)
> 3761                        else if( ind[2] > 255 )
> (gdb)
> 3763                        str_to_uc_cpy( includedCol, included.get() );
> (gdb)
> 3764                    }
> (gdb)
> 3754                while( ( ret =3D SQLGetData( m_hstmt, 3,
> SQL_C_WCHAR, included.get(), 255, &ind[2] ) ) !=3D SQL_NO_DATA )
> (gdb)
> 3771                includedCol.erase( 0, 1 );
> (gdb) p ind[2]
> $2 =3D 4
> (gdb) p ret
> $3 =3D 100
> (gdb) n
>
> This is what happens with column 3 when the array is empty.
>
> 3779            while( ( ret =3D SQLGetData( m_hstmt, pos, SQL_C_WCHAR,
> index_param.get(), 255, &ind[3] ) ) !=3D SQL_NO_DATA )
> (gdb)
> 3781                if( ret =3D=3D SQL_SUCCESS || ret =3D=3D SQL_SUCCESS_=
WITH_INFO )
> (gdb) p ind[3]
> $4 =3D -1
> (gdb) p ret
> $5 =3D 0
> (gdb) n
> 3783                    auto numBytes =3D ind[3];
> (gdb)
> 3784                    if( ind[3] =3D=3D SQL_NO_TOTAL )
> (gdb)
> 3786                    else if( ind[3] > 255 )
> (gdb)
> 3788                    str_to_uc_cpy( options, index_param.get() );
> (gdb)
> 3789                }
> (gdb)
> 3779            while( ( ret =3D SQLGetData( m_hstmt, pos, SQL_C_WCHAR,
> index_param.get(), 255, &ind[3] ) ) !=3D SQL_NO_DATA )
> (gdb)
> 3781                if( ret =3D=3D SQL_SUCCESS || ret =3D=3D SQL_SUCCESS_=
WITH_INFO )
> (gdb) p ind[3]
> $6 =3D -1
> (gdb) p ret
> $7 =3D 0
> (gdb)
>
> And this one is for column 4 of the query.
>
> The column is NULL, so no data is there.
>
> I think it's a bug in the driver as it should return SQL_NO_DATA on
> the very first call....
>
> Thank you.

Using following:

[quote]
WaylandGnome /home/igor/dbhandler/Debug # emerge -pv psqlodbc
 * Last emerge --sync was 1y 348d 19h 34m 58s ago.

 * IMPORTANT: config file '/etc/portage/package.keywords' needs updating.
 * See the CONFIGURATION FILES and CONFIGURATION FILES UPDATE TOOLS
 * sections of the emerge man page to learn how to update config files.

These are the packages that would be merged, in order:

Calculating dependencies... done!
Dependency resolution took 30.63 s (backtrack: 0/20).

[ebuild   R    ] dev-db/psqlodbc-11.01.0000::gentoo  USE=3D"ssl -doc
-iodbc -threads" 0 KiB

Total: 1 package (1 reinstall), Size of downloads: 0 KiB
WaylandGnome /home/igor/dbhandler/Debug #
[/quote]

Thank you.

>
> > >
> > > Dave