mysql誤刪除root用戶或者忘記root密碼時的解決辦法
一不小心刪除了mysql的root用戶，在網上找了很多辦法都沒有解決，由於mysql數據庫比較多，重裝又太麻煩，所以一直在努力嘗試各種方法，最後終於成功了。步驟如下：
1、先結束mysqld進程
#killall mysqld
不加載grant_tables而進入mysql
#mysqld_safe --skip-grant-tables &
進入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用戶的表）
Query OK, 1 row affected, 3 warnings (0.00 sec)
(這時可能會提示某字段如ssl_cipher無默認值, 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';
(這裏面是修改root用戶的權限)
mysql> quit;
2、帶權限正常啓動mysql
#service mysqld start
3、使用root用戶登錄（如果有phpadmin就直接用root空密碼登錄再修改密碼或權限就可以了）
#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
試下沒有密碼時進入mysql
#mysql -u root
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)
使用密碼進入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>