问题
I have installed ubuntu 16.04 server. Mysql server was installed by default in it. When I am trying to access the mysql with mysql -u root -p, I am unable to log in to mysql because I dont have the password. Is there any default password?
I have also tried with --skip-grant-tables, even this does not work. Even trying to log in with just mysql -u root is a failure.
回答1:
This is what you are looking for:sudo mysql --defaults-file=/etc/mysql/debian.cnf
MySql on Debian-base Linux usually use a configuration file with the credentials.
回答2:
I had a fresh installation of mysql-server on Ubuntu 18.10 and couldn't login with default password. Then only I got to know that by default root user is authenticated using auth_socket. So as in the answer when the plugin changed to mysql_native_password, we can use mysql default password
$ sudo apt install mysql-server
$ sudo cat /etc/mysql/debian.cnf
You can find the following lines in there
user = debian-sys-maint
password = password_for_the_user
Then:
$ mysql -u debian-sys-maint -p
Enter password:
type the password from debian.cnf
mysql> USE mysql
mysql> SELECT User, Host, plugin FROM mysql.user;
+------------------+-----------+-----------------------+
| User | Host | plugin |
+------------------+-----------+-----------------------+
| root | localhost | auth_socket |
| mysql.session | localhost | mysql_native_password |
| mysql.sys | localhost | mysql_native_password |
| debian-sys-maint | localhost | mysql_native_password |
+------------------+-----------+-----------------------+
4 rows in set (0.00 sec)
mysql> UPDATE user SET plugin='mysql_native_password' WHERE User='root';
mysql> COMMIT;
Either:
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'new_password';
Or:
// For MySQL 5.7+
mysql>UPDATE mysql.user SET authentication_string=PASSWORD('new_password') where user='root';
--Update--
Sometimes you will need to restart your mysql server.
sudo service mysql restart
or
sudo systemctl restart mysql
回答3:
Mysql by default has root user's authentication plugin as auth_socket, which requires the system user name and db user name to be the same.
Specifically, log in as root or sudo -i and just type mysql and you will be logged in as mysql root, you can then create other operating users.
If you do not have a root on host, I guess you should not be allowed to login to mysql as root?
回答4:
You can simply reset the root password by running the server with --skip-grant-tables and logging in without a password by running the following as root or with sudo:
service mysql stop
mysqld_safe --skip-grant-tables &
mysql -u root
mysql> use mysql;
mysql> update user set authentication_string=PASSWORD("YOUR-NEW-ROOT-PASSWORD") where User='root';
mysql> flush privileges;
mysql> quit
# service mysql stop
# service mysql start
$ mysql -u root -p
回答5:
Although this is an old question, there are several of us still struggle to find an answer. At least I did. Please don't follow all the lengthy solutions. You could simply login to your mysql as root without providing any password (provided it is a fresh installation or you haven't changed the password since your installation) by adding sudo before your mysql command.
$sudo mysql -uroot -p
mysql>
This is because mysql changed the security model in one of the latest versions.
Hope this helps
回答6:
- the first you should stop mysql
- use this command
sudo mysqld_safe --skip-grant-tables --skip-networking & - and then input
mysql -u roottry this way,I have been solved my problem with this method.
回答7:
Note that in Ubuntu systems running MySQL 5.7 (and later versions), the root MySQL user is set to authenticate using the auth_socket plugin by default rather than with a password. you will need to switch its authentication method from auth_socket to mysql_native_password
as @BeNiza said, they changed the security model. I did following steps and it works for mysql 5.7.27 on ubuntu 18.04
sudo apt install mysql-server
The MySQL database software is now installed, but its configuration is not yet complete.
To secure the installation, MySQL comes with a script that will ask whether we want to modify some insecure defaults. Initiate the script by typing:
sudo mysql_secure_installation
you should press Y and hit the ENTER key at each prompt.
This will cause issues if you use a weak password
You can simply login to your mysql as root without providing any password by adding sudo before your mysql command.
sudo mysql
mysql> ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'your-password';
If you set a weak password you would see the following error:
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
mysql> FLUSH PRIVILEGES;
mysql> exit
Note: After configuring your root MySQL user to authenticate with a password, you’ll no longer be able to access MySQL with the sudo mysql command used previously. Instead, you must run the following:
mysql -u root -p
After entering the password you just set, you will see the MySQL prompt.
回答8:
I think another place to look is /var/lib.
If you go there you can see three mysql folders with 'interesting' permissions:
user group
mysql mysql
Here is what I did to solve my problem with root password:
after running
sudo apt-get purge mysql*
sudo rm -rf /etc/mysql
I also ran the following (instead of my_username put yours):
cd /var/lib
sudo chown --from=mysql <my_username> mysql* -R
sudo rm -rf mysql*
And then:
sudo apt-get install mysql-server
which prompted me to select a new root password. I hope it helps
回答9:
Simply run sudo dpkg-reconfigure mysql-server-5.7
You can find the version you have installed by running dpkg --get-selections | grep mysql-server
来源：https://stackoverflow.com/questions/42421585/default-password-of-mysql-in-ubuntu-server-16-04