#准备工作
1、停机
[root@localhost local]# /etc/init.d/mysqld stop
Shutting down MySQL..                                      [确定]2、切换版本
[root@localhost local]# mv /root/mysql-5.6.27-linux-glibc2.5-x86_64.tar.gz ./mysql-5.7
[root@localhost local]# ln -s mysql-5.7 mysql[root@localhost local]# ls -l
总用量 48
drwxr-xr-x.  2 root  root  4096 9月  23 2011 bin
drwxr-xr-x.  2 root  root  4096 9月  23 2011 etc
drwxr-xr-x.  2 root  root  4096 9月  23 2011 games
drwxr-xr-x.  2 root  root  4096 9月  23 2011 include
drwxr-xr-x.  2 root  root  4096 9月  23 2011 lib
drwxr-xr-x.  2 root  root  4096 9月  23 2011 lib64
drwxr-xr-x.  2 root  root  4096 9月  23 2011 libexec
lrwxrwxrwx.  1 root  root     9 11月 12 03:52 mysql -> mysql-5.7
drwxr-xr-x. 13 mysql mysql 4096 11月 12 03:24 mysql-5.6
drwxr-xr-x.  9  7161 wheel 4096 10月 12 15:29 mysql-5.7
drwxr-xr-x.  2 root  root  4096 9月  23 2011 sbin
drwxr-xr-x.  5 root  root  4096 10月 22 02:36 share
drwxr-xr-x.  2 root  root  4096 9月  23 2011 src
3、启动 5.7
[root@localhost local]# /etc/init.d/mysqld start
Starting MySQL...
[确定]4、运行mysql_upgrade -s  -s 只更新系统表
[root@localhost local]# mysql_upgrade -s
The --upgrade-system-tables option was used, databases won't be touched.
Checking if update is needed.
Checking server version.
Running queries to upgrade MySQL server.
Upgrading the sys schema.
Upgrade process completed successfully.
Checking if update is needed.5、查看升级后的库
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
| test               |
+--------------------+
5 rows in set (0.00 sec)#注意多了个sys库，表示升级成功！#降级
http://dev.mysql.com/doc/refman/5.7/en/downgrading-to-previous-series.html