//下载5.7版本的mysql brew install mysql@5.7 //启动 brew services start mysql@5.7
上面是用homebrew安装5.7版本的mysql，但是不知道为什么登录报错，之前没有出现过这个问题。这里我只是记录一下用brew安装指定版本mysql。
安装tar包mysql
参考：https://blog.csdn.net/zmx729618/article/details/72769840
开机启动
mysql安装完成时候每次开机之后都要重新启动一下，很麻烦，所以要配置mysql开机启动。
配置参考:https://www.cnblogs.com/wangziyue/p/10658730.htm
问题记录
配置开机启动之后发现没有自启动成功，这个时候要查看mysql启动日志，来判断原因。
但是mysql的启动日志是要配置才有的，所以涉及到配置my.cnf文件。
在 /etc/my.cnf文件的[mysqld]节点添加关于errorlog的配置。如果没有my.cnf文件自己建一个，把下面的东西粘贴进去
https://www.cnblogs.com/weslie/articles/8553391.html
# Example MySQL config file for medium systems. # # This is for a system with little memory (32M - 64M) where MySQL plays # an important part, or systems up to 128M where MySQL is used together with # other programs (such as a web server) # # MySQL programs look for option files in a set of # locations which depend on the deployment platform. # You can copy this option file to one of those # locations. For information about these locations, see: # http://dev.mysql.com/doc/mysql/en/option-files.html # # In this file, you can use all long options that a program supports. # If you want to know which options a program supports, run the program # with the "--help" option. # The following options will be passed to all MySQL clients [client] default-character-set=utf8 #password = your_password port = 3306 socket = /tmp/mysql.sock # Here follows entries for some specific programs # The MySQL server [mysqld] user=mysql log-error=/usr/local/mysql/log/error.log character-set-server=utf8 init_connect='SET NAMES utf8 port = 3306 socket = /tmp/mysql.sock skip-external-locking key_buffer_size = 16M max_allowed_packet = 1M table_open_cache = 64 sort_buffer_size = 512K net_buffer_length = 8K read_buffer_size = 256K read_rnd_buffer_size = 512K myisam_sort_buffer_size = 8M character-set-server=utf8 init_connect='SET NAMES utf8' # Don't listen on a TCP/IP port at all. This can be a security enhancement, # if all processes that need to connect to mysqld run on the same host. # All interaction with mysqld must be made via Unix sockets or named pipes. # Note that using this option without enabling named pipes on Windows # (via the "enable-named-pipe" option) will render mysqld useless! # #skip-networking # Replication Master Server (default) # binary logging is required for replication log-bin=mysql-bin # binary logging format - mixed recommended binlog_format=mixed # required unique id between 1 and 2^32 - 1 # defaults to 1 if master-host is not set # but will not function as a master if omitted server-id = 1 # Replication Slave (comment out master section to use this) # # To configure this host as a replication slave, you can choose between # two methods : # # 1) Use the CHANGE MASTER TO command (fully described in our manual) - # the syntax is: # # CHANGE MASTER TO MASTER_HOST=<host>, MASTER_PORT=<port>, # MASTER_USER=<user>, MASTER_PASSWORD=<password> ; # # where you replace <host>, <user>, <password> by quoted strings and # <port> by the master's port number (3306 by default). # # Example: # # CHANGE MASTER TO MASTER_HOST='125.564.12.1', MASTER_PORT=3306, # MASTER_USER='joe', MASTER_PASSWORD='secret'; # # OR # # 2) Set the variables below. However, in case you choose this method, then # start replication for the first time (even unsuccessfully, for example # if you mistyped the password in master-password and the slave fails to # connect), the slave will create a master.info file, and any later # change in this file to the variables' values below will be ignored and # overridden by the content of the master.info file, unless you shutdown # the slave server, delete master.info and restart the slaver server. # For that reason, you may want to leave the lines below untouched # (commented) and instead use CHANGE MASTER TO (see above) # # required unique id between 2 and 2^32 - 1 # (and different from the master) # defaults to 2 if master-host is set # but will not function as a slave if omitted #server-id = 2 # # The replication master for this slave - required #master-host = <hostname> # # The username the slave will use for authentication when connecting # to the master - required #master-user = <username> # # The password the slave will authenticate with when connecting to # the master - required #master-password = <password> # # The port the master is listening on. # optional - defaults to 3306 #master-port = <port> # # binary logging - not required for slaves, but recommended #log-bin=mysql-bin # Uncomment the following if you are using InnoDB tables #innodb_data_home_dir = /usr/local/mysql/data #innodb_data_file_path = ibdata1:10M:autoextend #innodb_log_group_home_dir = /usr/local/mysql/data # You can set .._buffer_pool_size up to 50 - 80 % # of RAM but beware of setting memory usage too high #innodb_buffer_pool_size = 16M #innodb_additional_mem_pool_size = 2M # Set .._log_file_size to 25 % of buffer pool size #innodb_log_file_size = 5M #innodb_log_buffer_size = 8M #innodb_flush_log_at_trx_commit = 1 #innodb_lock_wait_timeout = 50 [mysqldump] quick max_allowed_packet = 16M [mysql] no-auto-rehash # Remove the next comment character if you are not familiar with SQL #safe-updates default-character-set=utf8 [myisamchk] key_buffer_size = 20M sort_buffer_size = 20M read_buffer = 2M write_buffer = 2M [mysqlhotcopy] interactive-timeout
这里就是日志文件位置，记住一定要把这个文件设置为可读可写，要不然也会报错。
设置文件可读可写
sudo chmod 777 error.log
然后就看看日志排错吧。