Re: PQftype() and Oid
От | Andro |
---|---|
Тема | Re: PQftype() and Oid |
Дата | |
Msg-id | da7021e0608070034w5b40b060qf7c7b8b9094b9afa@mail.gmail.com обсуждение исходный текст |
Ответ на | PQftype() and Oid (Andro <andromede@gmail.com>) |
Список | pgsql-interfaces |
While I agree this is a reliable way of matching, this has a significant impact on performance to make an extra query on each field that I want the type of ! And this makes this approach definitly not the one to implement IMO. Best, Charles On 8/5/06, Volkan YAZICI <yazicivo@ttnet.net.tr> wrote: > On Aug 04 04:38, Andro wrote: > > Oids are in pg_type catalog (server side) and src/include/catalog/pg_type.h > > (hard-wired). > > > > But what should we compare the Oid returned by PQftype() with? > > Let's say I want to check if column 1 is a VARCHAR, do I have to > > > > if (PQftype(res,1) == 1043) > > ...; > > > > ? > > Isn't there a kind of enum which we could rely on to find out types? What if > > Oids change in pg_type.h? > > You can make another query on pg_type to learn OID of a specific type. > And then compare it with the returned one from PQftype(main_query_res). > > Furthermore, I think this is the only reliable way of accomplising this > task. (IIRC, PHP PostgreSQL API does same too.) Otherwise, when you use > hard-wired headers (e.g. by including pg_type.h) what will you do when > related server has a custom type that isn't get shippied with the > PostgreSQL headers you included. > > > Regards. >
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