> > > > I tried to clean the default information in the mysql database that
> > > > located in user table. When use the >mysql -uroot -proot
> > > > it is working, but when I clean and delete some data in the user table
> > > > by calling the following SQL statement:
> > > > DELETE FROM user WHERE User= ' ';
> > > > DELETE FROM user WHERE User=' ' AND HOST='localhost';
> > > > DELETE FROM user WHERE User='root' AND P***word=' ';
>
> > > > after calling the above SQL statement, then I try to
> > > > use >mysql -uroot -proot

Did you ever actually grant privileges to user: root with p***word:
root on host: localhost? I don't remember the default set up of mysql
having root;root as being set up. The system might have been confused
and just ***umed you were entering as root with any valid p***word...

So, my understanding is that you cannot even get into the system to
make changes? If that's the case, you should follow the directions
here:
http://dev.mysql.com/doc/refman/5.1/...rmissions.html
so you can get back on the system and check to see what you did wrong.
Be very sure about your tables before you flush privileges (especially
when making manual changes) so something like this doesn't happen
again.

Nino