Re: Get Unix timestamp from SQL timestamp through libpq

On Mon, Jan 11, 2010 at 1:16 AM, Yan Cheng Cheok <yccheok(at)yahoo(dot)com> wrote:
> I know I can convert SQL timestamp to unix timestamp, using the following way.
>
> SELECT extract(epoch FROM now());
>
> Now, I have a stored procedure function, which will directly return a table row to the caller. One of the row field is "timestamp" type.
>
> In my application, I am using libpq. I wish to use libpq functions (or any c/c++ function), to convert "2010-01-11 13:10:55.283" into unix timestamp. Off course, I can create another stored procedure named
>
> SQLTimestamp2UnixTimestamp
> SELECT extract(epoch FROM $1);
>
> But I just wish to accomplish this task with a single c/c++ function call, without involving stored procedure.

libpqtypes can do this (and it's much faster if you use libpqtypes to
issue the query).

PGtimestamptz ts;
res = PQexef("select now()");
PQgetf(res, 0, "%timestamptz", 0 , &ts);
int epoch = ts.epoch;

http://libpqtypes.esilo.com/

merlin