Re: How do I check for NULL

Adrian Klaver <adrian.klaver@aklaver.com>

From: Adrian Klaver <adrian.klaver@aklaver.com>
To: Igor Korot <ikorot01@gmail.com>, "David G. Johnston" <david.g.johnston@gmail.com>
Cc: "pgsql-generallists.postgresql.org" <pgsql-general@lists.postgresql.org>
Date: 2025-12-09T16:09:51Z
Lists: pgsql-general
On 12/8/25 23:53, Igor Korot 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>
>>

Read:

https://www.postgresql.org/docs/current/sql-syntax-lexical.html#SQL-SYNTAX-IDENTIFIERS

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


-- 
Adrian Klaver
adrian.klaver@aklaver.com