linux ÏÂc++¼°mysql¶Ôʱ¼ä´¦ÀíµÄ³£Óü¼ÇÉ

mysql ½Øȡijһ¸öʱ¼ä(datetimeÀàÐÍ)µÄÈÕÆÚ£º
·½·¨1£ºselect date(row_name) from table_name where row = row1;
·½·¨2£ºselect left(row_name, 10) from table_name where row = row1;
·½·¨3£ºselect cast(row_name as char[10]) from table_name where row = row1;
È¡µÃij¸öÈÕÆÚµÄtime_tÊýÖµ£ºselect unix_timestamp(date(row_name)) from table_name where row = row1;
ÒÔtime_tΪ²ÎÊýÈ¡µÃij¸öʱ¼ä
time_t ÊÇ'1970-01-01 00:00:00'ÒÔÀ´µÄÃëÊý
select '1970-01-01 00:00:00'+ INTERVAL time_t_num SECOND ;
È¡µÃµ±Ç°ÈÕÆÚ£ºselect curdate();
È¡µÃµ±Ç°Ê±¼ä£ºselect now();
½«ÈÕÆÚת»¯Îª¶ÌÈÕÆÚ¸ñʽ
SELECT REPLACE(date(row_name),  '-0',  '-');
linuxÏÂc++³£ÓÃʱ¼ä´¦Àíº¯Êý
clock()ÓÃÀ´³ÌÐò¼Æʱ
ÀýÈ磺 ÒÔÏÂÕª×Ô
#include “stdio.h”
#include “stdlib.h”
#include “time.h”
int main( void )
{
   long    i = 10000000L;
   clock_t start, finish;
   double  duration;
   /* ²âÁ¿Ò»¸öʼþ³ÖÐøµÄʱ¼ä*/
   printf( "Time to do %ld empty loops is ", i );
   start = clock();
   while( i-- )      ;
   finish = clock();
   duration = (double)(finish - start) / CLOCKS_PER_SEC;
   printf( "%f seconds\n", duration );
   system("pause");
}
ʾÀý³ö´¦£ºDIY²¿Âä(http://www.diybl.com/course/3_program/vc/vc_js/20090307/159296.html)
time_tÀàÐÍ
time_t  t = time(NULL);
time_tת³ÉtmÀàÐÍ
struct tm*  t_tm = localtime(time(NULL));
time_tת³É×Ö·û´®¸ñʽ
struct tm* tm_ago = localtime(&t);
sprintf(date_days_ago, "%04d-%02d-%02d", 1900+tm_ago->tm_year,
                                tm_ago->tm_mon+1, tm_ago->tm_mday);
 
time_t t_now = time(NULL);   //seconds since 1970-01-01
        struct