Re: How do I check for NULL

David G. Johnston <david.g.johnston@gmail.com>

From: "David G. Johnston" <david.g.johnston@gmail.com>
To: Igor Korot <ikorot01@gmail.com>
Cc: "pgsql-generallists.postgresql.org" <pgsql-general@lists.postgresql.org>
Date: 2025-12-09T13:43:57Z
Lists: pgsql-general
Tuesday, December 9, 2025, Igor Korot <ikorot01@gmail.com> wrote:

> Hi, Davd,
>
> On Mon, Dec 8, 2025 at 6:44 PM David G. Johnston
> <david.g.johnston@gmail.com> wrote:
> >
> > On Monday, December 8, 2025, Igor Korot <ikorot01@gmail.com> wrote:
> >>
> >>
> >> However,, I'd like to still insert the record and I'd like to do
> something like:
> >>
> >> INSERT INTO test VALUES( 0, 'abc', 12345, IF( (SELECT foo FROM bar) ==
> >> NULL, "postgres", <select_result>), /*more data follow*/);
> >>
> >> What would be the best way to achieve this?
> >
> >
> > The “coalesce” function.
>
> This is the query I use for my ODBC calls:
>
>             qry2 = L"INSERT INTO \"test\" VALUES( ?, ?, (SELECT c.oid
> FROM pg_class c, pg_namespace nc WHERE nc.oid = c.relnamespace AND
> c.relname = ? AND nc.nspname = ?), COALESCE((SELECT tableowner FROM
> pg_tables WHERE tablename = ? AND schemaname = ?), \"postgres\"), ...)
> ON CONFLICT DO NOTHING;";
>
> Calling SQLExecute after parameter binding results in
>
> "L"ERROR: column \"postgres\" does not exist;\nError while preparing
> parameters"std::basic_string<wchar_t,std::char_traits<
> wchar_t>,std::allocator<wchar_t>
>
>
Use single quotes for a string literal value.

David J.