王新阳

mysqlnd cannot connect to MySQL 4.1+ using the old insecure authentication. Please use an administration tool to reset your password with the command SET PASSWORD = PASSWORD('your_existing_password'). This will store a new, and more secure, hash value in mysql.user. If this user is used in other scripts executed by PHP 5.2 or earlier you might need to remove the old-passwords flag from your my.cnf file

解决方法如下：

SET old_passwords = 0;
UPDATE mysql.user SET PASSWORD = PASSWORD( 'root' ) WHERE User = 'root' LIMIT 1 ;
SELECT LENGTH( PASSWORD ) FROM mysql.user WHERE User = 'root';
FLUSH PRIVILEGES ;