Re: Determine server version from psql script

Igor Korot <ikorot01(at)gmail(dot)com> writes:
> On Sat, Mar 22, 2025, 8:58 PM David G. Johnston <david(dot)g(dot)johnston(at)gmail(dot)com>
> wrote:
>> Then read the psql docs. Your version has \if and you’ll find server
>> version listed as the available client variables.

> I was hoping for something like

> If server_version >= X:
> CREATE OR REPLACE TRIGGER...

psql's \if doesn't (yet) have any native expression evaluation
ability, so you have to farm out the ">=" comparison. The
psql docs suggest relying on the server to do it, which would
go along the lines of

select current_setting('server_version_num')::int >= 130000 as v13
\gset
\if :v13
... do something
\else
... do something else
\endif

You could also do the comparison client-side, along the lines of

\set v13 `expr :SERVER_VERSION_NUM \>= 130000`
\if :v13
... etc

But that introduces assorted platform dependencies and requires
close attention to correct shell quoting, so it's seldom
preferable IMO.

regards, tom lane