> how can i use unix timestamp as a data type?
the datetime data type should work. you can find info about it at
http://www.postgresql.org/idocs/index.php?functions-datetime.html
http://www.postgresql.org/idocs/index.php?datatype-datetime.html
here is some example code
CREATE TABLE test (
id integer PRIMARY KEY,
mytime datetime
);
#include <time.h>
...
time_t mytime = time (NULL);
printf ("time to be inserted into database: %s\n", ctime (&mytime));
/* insert row setting the time. if you want to insert the current time you
can pass 'now' to a datetime field */
sprintf (sql_str, "INSERT INTO test (id, mytime) VALUES (1, '%s')", ctime
(&mytime));
res = PQexec(dbconn, sql_str);
...
/* get row extracting the time since the epoch */
sprintf (sql_str, "SELECT id, extract (epoch from mytime) FROM test WHERE
oid = %d", PQoidValue(res));
...
mytime = atoi(PQgetvalue(res, 0, 1));
printf ("time retrieved from database: %s\n", ctime(&mytime));
