我正在尝试在mac os 10.6上使用Homebrew by brew安装MySQL 5.1.52。
一切都很顺利，我也成功地使用mysql_install_db。
然而，当我试图连接到服务器使用:
/usr/local/Cellar/mysql/5.1.52/bin/mysqladmin -u root password 'mypass'
我得到:
/usr/local/Cellar/mysql/5.1.52/bin/mysqladmin: connect to server at 'localhost'
failed error: 'Access denied for user 'root'@'localhost' (using password: NO)'
我尝试访问mysqladmin或mysql使用-u root - root以及，
但是有没有密码都不行。
这是全新机器上的全新安装，据我所知，新安装必须在没有根密码的情况下访问。我还试过:
/usr/local/Cellar/mysql/5.1.52/bin/mysql_secure_installation
但我也得到了
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)
博士TL;
MySQL服务器在安装Brew后可能无法运行。尝试brew services启动mysql或只启动mysql。如果您不希望MySQL作为后台服务运行，请启动服务器。
完整的故事:
我刚刚在一台运行Sierra的新MacBook Pro上安装了MySQL(稳定)5.7.17，在运行mysql_secure_installation时也得到了一个错误:
Securing the MySQL server deployment.
Enter password for user root:
Error: Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)
你说什么?
根据Brew的安装信息，mysql_secure_installation应该会提示我…安装安全。我认为MySQL服务器可能没有运行，这是正确的。运行brew服务启动mysql，然后运行mysql_secure_installation。
下面是MySQL 5.7的更新
bash --version
GNU bash, version 4.4.12(1)-release (x86_64-apple-darwin17.0.0)
Copyright (C) 2016 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
#========================================
brew --version
Homebrew 1.7.6
Homebrew/homebrew-core (git revision eeb08; last commit 2018-09-27)
Homebrew/homebrew-cask (git revision c9f62; last commit 2018-09-27)
#========================================
mysql --version
mysql Ver 14.14 Distrib 5.7.23, for osx10.13 (x86_64) using EditLine wrapper
#========================================
system_profiler SPSoftwareDataType
Software:
System Software Overview:
System Version: macOS 10.13.3 (17D47)
Kernel Version: Darwin 17.4.0
Boot Volume: Macintosh HD
Boot Mode: Normal
Computer Name: EdisonMacHomeBj
User Name: Edison (edison)
Secure Virtual Memory: Enabled
System Integrity Protection: Disabled
Time since boot: 6 days 23:13
brew remove mysql@5.7
brew cleanup
mv /usr/local/var/mysql /usr/local/var/mysql.bak
brew install mysql@5.7
rm -rf /usr/local/var/mysql
#========================================
mysqld --initialize
2018-09-28T04:54:06.526061Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2018-09-28T04:54:06.542625Z 0 [Warning] Setting lower_case_table_names=2 because file system for /usr/local/var/mysql/ is case insensitive
2018-09-28T04:54:07.096637Z 0 [Warning] InnoDB: New log files created, LSN=45790
2018-09-28T04:54:07.132950Z 0 [Warning] InnoDB: Creating foreign key constraint system tables.
2018-09-28T04:54:07.196824Z 0 [Warning] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: 87cf2f10-c2da-11e8-ac2d-ba163df10130.
2018-09-28T04:54:07.224871Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened.
2018-09-28T04:54:07.366688Z 0 [Warning] CA certificate ca.pem is self signed.
2018-09-28T04:54:07.457954Z 1 [Note] A temporary password is generated for root@localhost: kq3K=JR8;GqZ
#========================================
mysql_secure_installation -uroot -p"kq3K=JR8;GqZ"
mysql_secure_installation: [Warning] Using a password on the command line interface can be insecure.
Securing the MySQL server deployment.
The existing password for the user account root has expired. Please set a new password.
New password:
Re-enter new password:
VALIDATE PASSWORD PLUGIN can be used to test passwords
and improve security. It checks the strength of password
and allows the users to set only those passwords which are
secure enough. Would you like to setup VALIDATE PASSWORD plugin?
Press y|Y for Yes, any other key for No: n
Using existing password for root.
Change the password for root ? ((Press y|Y for Yes, any other key for No) : y
New password:
Re-enter new password:
By default, a MySQL installation has an anonymous user,
allowing anyone to log into MySQL without having to have
a user account created for them. This is intended only for
testing, and to make the installation go a bit smoother.
You should remove them before moving into a production
environment.
Remove anonymous users? (Press y|Y for Yes, any other key for No) : y
Success.
Normally, root should only be allowed to connect from
'localhost'. This ensures that someone cannot guess at
the root password from the network.
Disallow root login remotely? (Press y|Y for Yes, any other key for No) : n
... skipping.
By default, MySQL comes with a database named 'test' that
anyone can access. This is also intended only for testing,
and should be removed before moving into a production
environment.
Remove test database and access to it? (Press y|Y for Yes, any other key for No) : n
... skipping.
Reloading the privilege tables will ensure that all changes
made so far will take effect immediately.
Reload privilege tables now? (Press y|Y for Yes, any other key for No) : y
Success.
All done!
