mysql——获取当前日期、时间的各种方式
1、当前时间的各种格式
2、now()和sysdate()的区别
验证2.sql语句测试:
mysql> select now(),sleep(3),now();
+---------------------+----------+---------------------+
| now() | sleep(3) | now() |
+---------------------+----------+---------------------+
| 2011-01-21 11:25:45 | 0 | 2011-01-21 11:25:45 |
+---------------------+----------+---------------------+
1 row in set (3.00 sec)
评:now()函数,每次取语句开始的执行时间.
mysql> select sysdate(),sleep(3),sysdate();
+---------------------+----------+---------------------+
| sysdate() | sleep(3) | sysdate() |
+---------------------+----------+---------------------+
| 2011-01-21 11:26:44 | 0 | 2011-01-21 11:26:47 |
+---------------------+----------+---------------------+
1 row in set (3.02 sec)
评:sysdate() 每次会取实际的时间。