mysql错误删除默认root用户解决办法

停止数据库，并在mysql配置文件my.cnf中添加
skip-grant-tables参数到[mysqld]配置块中
重启mysqld

use mysql;
insert into user set user='su',ssl_cipher='',x509_issuer='',x509_subject='';
update user set Host='localhost',select_priv='y', insert_priv='y',update_priv='y', Alter_priv='y',delete_priv='y',create_priv='y',drop_priv='y',reload_priv='y',shutdown_priv='y',Process_priv='y',file_priv='y',grant_priv='y',References_priv='y',index_priv='y',create_user_priv='y',show_db_priv='y',super_priv='y',create_tmp_table_priv='y',Lock_tables_priv='y',execute_priv='y',repl_slave_priv='y',repl_client_priv='y',create_view_priv='y',show_view_priv='y',create_routine_priv='y',alter_routine_priv='y',create_user_priv='y' where user='su';
update user set password=password('newpassword') where user='su';