Re: Does included columns part of the PK

On 3/14/26 9:56 AM, Igor Korot wrote:
> Hi,
>
> On Sat, Mar 14, 2026 at 8:51 AM David G. Johnston
> <david(dot)g(dot)johnston(at)gmail(dot)com <mailto:david(dot)g(dot)johnston(at)gmail(dot)com>> wrote:
>
> On Saturday, March 14, 2026, Adrian Klaver
> <adrian(dot)klaver(at)aklaver(dot)com <mailto:adrian(dot)klaver(at)aklaver(dot)com>> wrote:
>
> On 3/14/26 12:09 AM, Igor Korot wrote:
>
> Hi, ALL,
> Have one weird question ;-)
>
> When I connect with ODBC and call SQLPrimaryKey() the
> function returns
>
>
> Are you actually using the SQLPrimaryKeys(), not SQLPrimaryKey()?
>
> all fields including
> "included" fields.
>
>
> Define 'included' fields.
>
>
> They are referring to the unique index that backs the PK constraint.
>
>
> Not “they” - “He”. 😊
>
> And yes - that’s what I’m referring to.

From here:

https://www.ibm.com/docs/en/db2-for-zos/12.0.0?topic=functions-sqlprimarykeys-get-primary-key-columns-table:

1 TABLE_CAT VARCHAR(128) This is always null.
2 TABLE_SCHEM VARCHAR(128) The name of the schema containing TABLE_NAME.
3 TABLE_NAME VARCHAR(128) NOT NULL Name of the specified table.
4 COLUMN_NAME VARCHAR(128) NOT NULL Primary key column name.
5 KEY_SEQ SMALLINT NOT NULL Column sequence number in the primary key,
starting with 1.
6 PK_NAME VARCHAR(128) Primary key identifier. Contains a null value if
not applicable to the data

From here:

https://github.com/postgresql-interfaces/psqlodbc/blob/main/info.c

At line 4035 in SQLPrimaryKeys()

For case 1

/*
* Simplified query to remove assumptions about number of
* possible index columns. Courtesy of Tom Lane - thomas
* 2000-03-21
*/

[...]

"select ta.attname, ia.attnum, ic.relname, n.nspname, tc.relname"
" from pg_catalog.pg_attribute ta ... "

case 2

select ta.attname, ia.attnum, ic.relname, n.nspname, NULL"
" from pg_catalog.pg_attribute ta, ..."

If I am following correctly then:

attname = column_name
attnum = key_seq
ic.relname = pk_name
nspname = table_schem
tc.relname = table_name

So how are using it in your code and what are the actual results?

Also what is showing up in the Postgres logs?

>
> Thank you.
>
>
> David J.
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com