1、新建数据库centos_old.

mysql > create database centos_old;

2、使用select concat拼成所有rename table的语句。

    mysql -uroot -p -e "select concat('rename table centos.',table_name,' to centos_old.',table_name,';') from information_schema.TABLES where TABLE_SCHEMA='centos';" > rename_mysql_name.sql

打开rename_mysql_name.sql，把第一行删除。

rename_mysql_name.sql内容大概为：

   rename table centos.wp_commentmeta to centos_old.wp_commentmeta;
   rename table centos.wp_comments to centos_old.wp_comments;
   rename table centos.wp_forum_forums to centos_old.wp_forum_forums;
   rename table centos.wp_forum_groups to centos_old.wp_forum_groups;
   rename table centos.wp_forum_posts to centos_old.wp_forum_posts;
   rename table centos.wp_forum_threads to centos_old.wp_forum_threads;
   rename table centos.wp_forum_usergroup2user to centos_old.wp_forum_usergroup2user;
   rename table centos.wp_forum_usergroups to centos_old.wp_forum_usergroups;
   rename table centos.wp_links to centos_old.wp_links;
   rename table centos.wp_options to centos_old.wp_options;
   rename table centos.wp_postmeta to centos_old.wp_postmeta;
   rename table centos.wp_posts to centos_old.wp_posts;
   rename table centos.wp_term_relationships to centos_old.wp_term_relationships;
   rename table centos.wp_term_taxonomy to centos_old.wp_term_taxonomy;
   rename table centos.wp_terms to centos_old.wp_terms;
   rename table centos.wp_usermeta to centos_old.wp_usermeta;
   rename table centos.wp_users to centos_old.wp_users;

3、执行rename语句

mysql -uroot -p

这样就完成了centos数据库名更改为centos_old的操作。