Re: LIBPQ Question
От | Igor Shevchenko |
---|---|
Тема | Re: LIBPQ Question |
Дата | |
Msg-id | 200310270925.26056.igor@carcass.ath.cx обсуждение исходный текст |
Ответ на | Re: LIBPQ Question (Tomasz Myrta <jasiek@klaster.net>) |
Ответы |
PGEASY QUESTION
|
Список | pgsql-interfaces |
On Monday 27 October 2003 09:15, Tomasz Myrta wrote: > Dnia 2003-10-27 00:08, Użytkownik creid napisał: > > Problem: Assigning a COUNT(*) result into an integer variable in my C > > program consistently fails except when I assign the same result to a char > > variable. I can only assume that the internal data type the COUNT > > function uses is integer. > > > > Can anyone help put me in the proper mindset so I may deal with this, > > seemingly simple issue, to resolution. > > > > I need the integer result to to help me satisfy a dynamic memory > > requirement... COUNT(*) result will tell me how many rows of data I need > > to malloc and I cannot perform a math operation on a char variable. > > All libpq results are strings. > some_int_value=atoi(PQgetvalue(...)) Not true anymore with protocol v3, which added the binary format. Text format is still the default. > Anyway why do you need count(*) ? When you retrieve your rows, you can > always check how many are them using PQntuples(...) and then malloc your > memory tables. > > Regards, > Tomasz Myrta > > > ---------------------------(end of broadcast)--------------------------- > TIP 9: the planner will ignore your desire to choose an index scan if your > joining column's datatypes do not match -- Best regards, Igor Shevchenko
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