MySQL 5.7的默认根密码是什么

新安装后，不能像其他旧版本一样使用 root ID 和空/无密码登录到 MySQL 数据库

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最佳答案

After you installed MySQL-community-server 5.7 from fresh on linux, you will need to find the temporary password from /var/log/mysqld.log to login as root.

  1. grep 'temporary password' /var/log/mysqld.log
  2. Run mysql_secure_installation to change new password

ref: http://dev.mysql.com/doc/refman/5.7/en/linux-installation-yum-repo.html

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In case you want to install mysql or percona unattended (like in my case ansible), you can use following script:

# first part opens mysql log
# second part greps lines with temporary password
# third part picks last line (most recent one)
# last part removes all the line except the password
# the result goes into password variable


password=$(cat /var/log/mysqld.log | grep "A temporary password is generated for" | tail -1 | sed -n 's/.*root@localhost: //p')


# setting new password, you can use $1 and run this script as a file and pass the argument through the script


newPassword="wh@teverYouLikE"


# resetting temporary password


mysql -uroot -p$password -Bse "ALTER USER 'root'@'localhost' IDENTIFIED BY '$newPassword';"
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There's so many answers out there saying to reinstall mysql or use some combo of

mysqld_safe --skip-grant-tables

and / or

UPDATE mysql.user SET Password=PASSWORD('password')

and / or something else ...

... None of it was working for me

Here's what worked for me, on Ubuntu 18.04, from the top

With special credit to this answer for digging me out of the frustration on this ...

$ sudo apt install mysql-server
$ sudo cat /etc/mysql/debian.cnf

Note the lines which read:

user     = debian-sys-maint
password = blahblahblah

Then:

$ mysql -u debian-sys-maint -p
Enter password: // type 'blahblahblah', ie. 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;  // When you don't have auto-commit switched on

Either:

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'new_password';

Or:

// For MySQL 5.7+
UPDATE mysql.user SET authentication_string=PASSWORD('new_password') where user='root';

Then:

mysql> FLUSH PRIVILEGES;
mysql> COMMIT;  // When you don't have auto-commit switched on
mysql> EXIT


$ sudo service mysql restart
$ mysql -u root -p
Enter password: // Yay! 'new_password' now works!
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I just installed Linux Mint 19 (based on Ubuntu 18.04) on my machine. I installed MySQL 5.7 from the repo (sudo apt install mysql-server) and surprisingly during installation, the setup didn't prompt to enter root password. As a result I wasn't able to login into MySQL. I googled here and there and tried various answers I found on the net, including the accepted answer above. I uninstalled (purging all dpkgs with mysql in its name) and reinstalled again from the default Linux Mint repositories. NONE works.

After hours of unproductive works, I decided to reinstall MySQL from the official page. I opened MySQL download page (https://dev.mysql.com/downloads/repo/apt) for apt repo and clicked Download button at the bottom right.

Next, run it with dpkg:

sudo dpkg -i mysql-apt-config_0.8.10-1_all.deb

At the installation setup, choose the MySQL version that you'd like to install. The default option is 8.0 but I changed it to 5.7. Click OK to quit. After this, you have a new MySQL repo in your Software Sources.

Update your repo:

sudo apt update

Finally, install MySQL:

sudo apt install mysql-server

And now I was prompted to provide root password! Hope it helps for others with this same experience.

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I to was experiencing the same problem and the only thing I was able to do to make it work was to go this route: 

drop user admin@localhost;
flush privileges;
create user admin@localhost identified by 'admins_password'

This allowed me to recreate my username and enter a password for the user name.

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In my case the data directory was automatically initialized with the --initialize-insecure option. So /var/log/mysql/error.log does not contain a temporary password but:

[Warning] root@localhost is created with an empty password ! Please consider switching off the --initialize-insecure option.

What worked was:

shell> mysql -u root --skip-password
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'new_password';

Details: MySQL 5.7 Reference Manual > 2.10.4 Securing the Initial MySQL Account

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None of these answers worked for me on Ubuntu Server 18.04.1 and MySQL 5.7.23. I spent a bunch of time trying and failing at setting the password and auth plugin manually, finding the password in logs (it's not there), etc.

The solution is actually super easy:

sudo mysql_secure_installation

It's really important to do this with sudo. If you try without elevation, you'll be asked for the root password, which you obviously don't have.

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It seems things were designed to avoid developers to set the root user, a better solution would be:

sudo mysql -u root

Then create a normal user, set a password, then use that user to work.

create user 'user'@'localhost' identified by 'user1234';
grant all on your_database.* to 'user'@'localhost';
select host, user from mysql.user;

Then try to access:

mysql -u user -p

Boom!

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MySQL 5.7 changed the secure model: now MySQL root login requires a sudo

The simplest (and safest) solution will be create a new user and grant required privileges.

1. Connect to mysql

sudo mysql --user=root mysql

2. Create a user for phpMyAdmin

CREATE USER 'phpmyadmin'@'localhost' IDENTIFIED BY 'some_pass';
GRANT ALL PRIVILEGES ON *.* TO 'phpmyadmin'@'localhost' WITH GRANT OPTION;
FLUSH PRIVILEGES;

Reference - https://askubuntu.com/questions/763336/cannot-enter-phpmyadmin-as-root-mysql-5-7

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MySQL 5.7 or newer generates a default temporary password after fresh install.

To use MySQL first you would be required to get that password from the log file which is present at the /var/log/mysqld.log. So follow the following process:

  1. grep 'temporary password' /var/log/mysqld.log

  2. mysql_secure_installation

The second command is required to change the password for MySQL and also to make certain other changes like removing temporary databases, allow or disallow remote access to root user, delete anonymous users etc…

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After a lot of try, I could reset the default password with the following commands (Ubuntu and derivatives):

sudo -i
mkdir -p /var/run/mysqld
chown mysql:mysql /var/run/mysqld
/etc/init.d/mysql stop
mysqld_safe --skip-grant-tables &
mysql -uroot
use mysql;
update user set authentication_string=password('YOURPASSWORD') where user='root';
update user set plugin="mysql_native_password" where User='root';
flush privileges;
quit;
sudo /etc/init.d/mysql stop
sudo /etc/init.d/mysql start

Sometimes, even after typed in the terminal 

mkdir -p /var/run/mysqld
chown mysql:mysql /var/run/mysqld
/etc/init.d/mysql stop
mysqld_safe --skip-grant-tables &

I got the error that the mysqld don't exists. So, quit, and type the same commands again.

And the final command 

sudo /etc/init.d/mysql start

Sometimes doesn't work. Only after restart the computer.

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MySQL server 5.7 was already installed by default on my new Linux Mint 19.

But, what's the MySQL root password? It turns out that:

The default installation uses auth_socket for authentication, in lieu of passwords!

It allows a password-free login, provided that one is logged into the Linux system with the same user name. To login as the MySQL root user, one can use sudo:

sudo mysql --user=root

But how to then change the root password? To illustrate what's going on, I created a new user "me", with full privileges, with:

mysql> CREATE USER 'me'@'localhost' IDENTIFIED BY 'my_new_password';
mysql> GRANT ALL PRIVILEGES ON *.* TO 'me'@'localhost' WITH GRANT OPTION;
mysql> FLUSH PRIVILEGES;

Comparing "me" with "root":

mysql> SELECT user, plugin, HEX(authentication_string)  FROM mysql.user WHERE user = 'me' or user = 'root';
+------+-----------------------+----------------------------------------------------------------------------+
| user | plugin                | HEX(authentication_string)                                                 |
+------+-----------------------+----------------------------------------------------------------------------+
| root | auth_socket           |                                                                            |
| me   | mysql_native_password | 2A393846353030304545453239394634323734333139354241344642413245373537313... |
+------+-----------------------+----------------------------------------------------------------------------+

Because it's using auth_socket, the root password cannot be changed: the SET PASSWORD command fails, and mysql_secure_installation desn't attain anything...

==> To zap this alternate authentication mode and return the MySQL root user to using passwords:

ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'SOME_NEW_ROOT_PASSWORD';

A good explanation.

More details from the MySQL manual.

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As of Ubuntu 20.04 with MySql 8.0 : you can set the password that way:

  1. login to mysql with sudo mysql -u root

  2. change the password:

USE mysql;
UPDATE user set authentication_string=NULL where User='root';
FLUSH privileges;
ALTER USER 'root'@'localhost' IDENTIFIED WITH caching_sha2_password BY 'My-N7w_And.5ecure-P@s5w0rd';
FLUSH privileges;
QUIT

now you should be able to login with mysql -u root -p (or to phpMyAdmin with username root) and your chosen password.

P,S:

You can also login with user debian-sys-maint, the password is written in the file /etc/mysql/debian.cnf

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To do it in non interactive mode (from a script):

systemctl start mysqld
MYSQL_ROOT_TMP_PSW=$(grep 'temporary password' $logpath/mysqld.log |sed "s|.*: ||")


## POPULATE SCHEMAS WITH ROOT USER
/usr/bin/mysql --connect-expired-password -u root -p${MYSQL_ROOT_TMP_PSW} < "$mysql_init_script"

Here's the head of the init script

SET GLOBAL validate_password_policy=LOW;
FLUSH privileges;


SET PASSWORD = PASSWORD('MYSQL_ROOT_PSW');
FLUSH privileges;


GRANT ALL PRIVILEGES ON *.* TO 'root'@'%';
FLUSH privileges;


...

Then restart the service systemctl restart mysqld


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