mysql命令行快速清空数据库的方法
有时我们只想把数据库里的所有表删除掉，而数据库保留，这时可以用mysql命令实现。
这里我们以wordpress数据库为例说明如何操作。
1. 以root身份登录数据库
mysql -uroot -p
2. 先用select语句将数据库wordpress里的所有表名及DROP语句串联后显示出来：
SELECT concat('DROP TABLE IF EXISTS wordpress.', table_name, ';') FROM information_schema.tables WHERE table_schema = 'wordpress';
显示如下：
+------------------------------------------------------------+
| concat('DROP TABLE IF EXISTS wordpress.', table_name, ';') |
+------------------------------------------------------------+
| DROP TABLE IF EXISTS wordpress.wp_commentmeta; |
| DROP TABLE IF EXISTS wordpress.wp_comments; |
| DROP TABLE IF EXISTS wordpress.wp_links; |
| DROP TABLE IF EXISTS wordpress.wp_options; |
| DROP TABLE IF EXISTS wordpress.wp_postmeta; |
| DROP TABLE IF EXISTS wordpress.wp_posts; |
| DROP TABLE IF EXISTS wordpress.wp_term_relationships; |
| DROP TABLE IF EXISTS wordpress.wp_term_taxonomy; |
| DROP TABLE IF EXISTS wordpress.wp_termmeta; |
| DROP TABLE IF EXISTS wordpress.wp_terms; |
| DROP TABLE IF EXISTS wordpress.wp_usermeta; |
| DROP TABLE IF EXISTS wordpress.wp_users; |
+------------------------------------------------------------+
12 rows in set (0.00 sec)
3. 将上面内容复制到记事本并整理如下：
DROP TABLE IF EXISTS wordpress.wp_commentmeta;
DROP TABLE IF EXISTS wordpress.wp_comments;
DROP TABLE IF EXISTS wordpress.wp_links;
DROP TABLE IF EXISTS wordpress.wp_options;
DROP TABLE IF EXISTS wordpress.wp_postmeta;
DROP TABLE IF EXISTS wordpress.wp_posts;
DROP TABLE IF EXISTS wordpress.wp_term_relationships;
DROP TABLE IF EXISTS wordpress.wp_term_taxonomy;
DROP TABLE IF EXISTS wordpress.wp_termmeta;
DROP TABLE IF EXISTS wordpress.wp_terms;
DROP TABLE IF EXISTS wordpress.wp_usermeta;
DROP TABLE IF EXISTS wordpress.wp_users;
4. 复制上面内容到mysql命令行即可。