How can I retrieve double or int data type for libpq

Started by aalmost 8 years ago2 messagesgeneral
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#1a
372660931@qq.com

Hi

I wanna use C library to connect pgsql server and I got 2 questions:

1, If I can fetch a row's data instead of using PQgetvalue?

2, PQgetvalue will return all data as text, I would have to convert them into the relative data type, is there a way of getting data by its original format?

Thanks so much!

Shore

#2Laurenz Albe
laurenz.albe@cybertec.at
In reply to: a (#1)
Re: How can I retrieve double or int data type for libpq

a wrote:

I wanna use C library to connect pgsql server and I got 2 questions:

This is all well documented in
https://www.postgresql.org/docs/current/static/libpq.html

1, If I can fetch a row's data instead of using PQgetvalue?

PGgetvalue *is* the way to fetch the row's data.

There is no call to fetch *all* columns at once, but that is
not necessary.

2, PQgetvalue will return all data as text, I would have to convert them into the
relative data type, is there a way of getting data by its original format?

You will get the data in binary form if you specify a resultFormat of 1
with PQexecParams.

Note, however, that they will be in the native binary format of the *server*.

Yours,
Laurenz Albe
--
Cybertec | https://www.cybertec-postgresql.com