mysqldump

bash

mysqldump -u root -p dbname>a.sql
mysqldump --no-data -u root -p dbname>a.sql

mysqldump -u root -p dbname>a.sql
mysqldump --no-data -u root -p dbname>a.sql

mysql root grant

bash

[mysqld]
skip-grant-tables

[mysqld]
skip-grant-tables