Re: [HACKERS] PQfnumber and quoted identifiers

Andreas Pflug <pgadmin(at)pse-consulting(dot)de> writes:
> If you change it, please give me a chance to code it version-aware so
> quoting/non-quoting can be performed dependent on libpq in use.

If you want a run-time test, the most reliable way would be to directly
test what PQfnumber does --- for instance, make a query known to
contain the column name "foo", and see what PQfnumber(res, "\"foo\"")
returns. I'm not sure there is any other solution, since we can't
retroactively install a version identifier in old libpq releases.

For a compile-time test, you could perhaps look to see if
PG_DIAG_SQLSTATE or one of the other new macros in postgres_ext.h
is defined. Not sure you really want a compile-time test though;
it'd break very easily if you get linked against some other version
of the library.

As for the more general question of whether to offer libpq version
identification going forward, I have no strong opinion on whether
it's really useful or not. If it's wanted, I'm tempted to suggest
that PQparameterStatus() could be extended to recognize "libpq_version"
paralleling "server_version". Not sure about a clean way to expose
the version at compile time.

regards, tom lane