Re: PSQL commands: \quit_if, \quit_unless

Yes, that is a possibility, but this can already be queried into a :-variable, so it is less indispensable.

can you show some examples, please?

 SELECT COUNT(*) AS has_unit_extension
   FROM pg_extension WHERE extname='unit' \gset
 \echo :has_unit_extension
 1

So that

 \if ! :hash_unit_extension
 CREATE TABLE foo(id SERIAL, stuff UNIT);
 \else
 \echo "unit extension is not loaded"
 \quit
 \fi

Ok, for this example one may try:

 CREATE EXTENSION IF NOT EXISTS unit;

Or use the "ON_ERROR_STOP" setting, but that is the idea, SQL can be used to test anything server-side.

--
Fabien.