1、先结束mysqld进程 #killall mysqld

不加载grant_tables而进入mysql #mysqld_safe --skip-grant-tables &

进入mysql #/usr/local/mysql/bin/mysql

mysql> use mysql Database changed

mysql> select * from user; Empty set (0.00 sec)

mysql> insert into user set user='root',ssl_cipher='',x509_issuer='',x509_subject='';

(增加root用户的表） Query OK, 1 row affected, 3 warnings (0.00 sec) (这时可能会提示某字段如ssl_cipher无默认值,　只要加上,ssl_cipher=''; 其字段如有提示依次添加就OK了)

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='root';

(这里面是修改root用户的权限)

mysql> quit;

2、带权限正常启动mysql #service mysqld start

3、使用root用户登录（如果有phpadmin就直接用root空密码登录再修改密码或权限就可以了） #mysql -u root -p mysql> update user set password=password('123456') where user='root';

Query OK, 1 row affected (0.00 sec) Rows matched: 1 Changed: 1 Warnings: 0

mysql> flush privileges;

mysql> quit

试下没有密码时进入mysql #mysql -u root ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

使用密码进入mysql #mysql -u root -p 123456 Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 25 to server version: 4.1.20 Type 'help;' or '\h' for help. Type '\c' to clear the buffer. mysql>