mac下安装mysql

1.用homebrew安装mysql，安装目录是/usr/local/opt/mysql.在目录/usr/local/opt/mysql下有配置文件my.cnf.
2.如果mysql配置文件my.cnf内容很少，没有指明日志，那么要加上日志相关配置，如下：
log_error = /tmp/mysql-error.log

general_log=ON

general_log_file=/tmp/mysql.log

这样在指定目录下就有日志，包括“错误日志”。

3.
启动命令：sudo sh /usr/local/opt/mysql/bin/mysql.server start
停止命令：sudo sh /usr/local/opt/mysql/bin/mysql.server stop


/**********常见问题1，启动mysql报错，权限问题******/
启动时用了命令 sh /usr/local/opt/mysql/bin/mysql.server start

报错提示如下：
Starting MySQL

. ERROR! The server quit without updating PID file (/usr/local/var/mysql/taiwudeMacBook-Pro.local.pid).


根据错误提示，知道跟PID相关，此时再去看错误日志。如果配置文件my.conf中没有配置错误日志路径，就要加上一句，如（log_error = /tmp/mysql-error.log），这样就能在/tmp/mysql-error.log中查到启动时的报错详细信息。
错误日志如下：
160218 11:00:57 mysqld_safe Starting mysqld daemon with databases from /usr/local/var/mysql

2016-02-18 11:00:57 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).

2016-02-18 11:00:57 0 [Note] /usr/local/opt/mysql/bin/mysqld (mysqld 5.6.26-log) starting as process 3440 ...

2016-02-18 11:00:57 3440 [Warning] Can't create test file /usr/local/var/mysql/taiwudeMacBook-Pro.lower-test

2016-02-18 11:00:57 3440 [Warning] Can't create test file /usr/local/var/mysql/taiwudeMacBook-Pro.lower-test

2016-02-18 11:00:57 3440 [Note] Plugin 'FEDERATED' is disabled.

^G/usr/local/opt/mysql/bin/mysqld: Can't find file: './mysql/plugin.frm' (errno: 13 - Permission denied)

2016-02-18 11:00:57 3440 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.

2016-02-18 11:00:57 3440 [Note] InnoDB: Using atomics to ref count buffer pool pages


根据错误日志中的信息，可以大概知道是权限问题，启动命令应该加上sudo。

启动命令用 sudo sh /usr/local/opt/mysql/bin/mysql.server start，成功！