出现时区的问题，首先我们要检查操作系统的时区

		
[root@testing ~]# date
Tue Sep 28 10:33:03 CST 2021

[root@testing ~]# date -R
Tue, 28 Sep 2021 10:33:06 +0800

[root@testing ~]# date +"%Z %z"
CST +0800		
		
		

CST 表示“中国标准时间” +0800

然后在查询数据库时区设置

		
mysql> show variables like "%time_zone";
+------------------+--------+
| Variable_name    | Value  |
+------------------+--------+
| system_time_zone | CST    |
| time_zone        | SYSTEM |
+------------------+--------+
2 rows in set (0.00 sec)		
		
		

system_time_zone 当前时区是 CST，time_zone 表示数据库使用操作系统的时区设置。

临时修改时区 set time_zone='+8:00'; 设置当前时区，set global time_zone = '+8:00'; 设置全局时区。

		
#设置全局时区，即时生效，作用于所有session
mysql> set global time_zone='+8:00';
Query OK, 0 rows affected (0.00 sec)

		
		

永久修改时区，编辑 /etc/my.cnf 配置文件，在[mysqld]的下面添加或者修改如下内容

		
default-time_zone = '+8:00'		
		
		

最后检查时间设置

		
mysql> select now(), UTC_TIMESTAMP;
+---------------------+---------------------+
| now()               | UTC_TIMESTAMP       |
+---------------------+---------------------+
| 2021-09-28 10:51:45 | 2021-09-28 02:51:45 |
+---------------------+---------------------+
1 row in set (0.00 sec)

mysql> SELECT TIMEDIFF(NOW(), UTC_TIMESTAMP); 
+--------------------------------+
| TIMEDIFF(NOW(), UTC_TIMESTAMP) |
+--------------------------------+
| 08:00:00                       |
+--------------------------------+
1 row in set (0.00 sec)

mysql> select timediff(now(),convert_tz(now(),@@session.time_zone,'+00:00')); 
+----------------------------------------------------------------+
| timediff(now(),convert_tz(now(),@@session.time_zone,'+00:00')) |
+----------------------------------------------------------------+
| 08:00:00                                                       |
+----------------------------------------------------------------+
1 row in set (0.00 sec)		

mysql> select curtime(); 
+-----------+
| curtime() |
+-----------+
| 10:52:40  |
+-----------+
1 row in set (0.00 sec)
		
		

JDBC 时区设置

		
# serverTimezone=UTC 
jdbc.url=jdbc:mysql://localhost:3306/demo?serverTimezone=UTC&characterEncoding=utf-8 

# serverTimezone=GMT%2B8
jdbc.url=jdbc:mysql://localhost:3306/demo?serverTimezone=GMT%2B8&characterEncoding=utf-8 
 
# serverTimezone=Asia/Shanghai
jdbc.url=jdbc:mysql://localhost:3306/demo?serverTimezone=Asia/Shanghai&characterEncoding=utf-8