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From: Tom Lane <[email protected]>
To: Igor Korot <[email protected]>
Cc: David G. Johnston <[email protected]>
Cc: Adrian Klaver <[email protected]>
Cc: pgsql-generallists.postgresql.org <[email protected]>
Subject: Re: Determine server version from psql script
Date: Sat, 22 Mar 2025 23:01:41 -0400
Message-ID: <[email protected]> (raw)
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Igor Korot <[email protected]> writes:
> On Sat, Mar 22, 2025, 8:58 PM David G. Johnston <[email protected]>
> 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

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