【MySQL】重置MySQL的root密码与修改MySQL默认字符集

第一次在Rails开发中使用MySQL数据库，结果root密码也不知道如何安装的，始终无法登录root，于是想到重置密码，在网上找了很多办法，下面这个是最靠谱的：

新建一个脚本如下：

#!/bin/bashPATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/binexport PATH# Check if user is rootif [ $(id -u) != "0" ]; then    printf "Error: You must be root to run this script!\n"    exit 1fiecho "=========================================================================\n"printf "Reset MySQL root Password for LNMP  ,  Written by Licess \n"printf "=========================================================================\n"printf "LNMP is a tool to auto-compile & install Nginx+MySQL+PHP on Linux \n"printf "This script is a tool to reset mysql root password for lnmp \n"printf "For more information please visit http://www.lnmp.org \n"printf "\n"printf "Usage: sh reset_mysql_root_password.sh\n"printf "=========================================================================\n"mysql_root_password=""read -p "(Please input New MySQL root password):" mysql_root_passwordif [ "$mysql_root_password" = "" ]; thenecho "Error: Password can't be NULL!!\n"exit 1fiprintf "Stoping MySQL...\n"/etc/init.d/mysql stopprintf "Starting MySQL with skip grant tables\n"/usr/bin/mysqld_safe --skip-grant-tables >/dev/null 2>&1 &printf "using mysql to flush privileges and reset password\n"sleep 10printf "update user set password = Password('$mysql_root_password') where User = 'root'\n"/usr/bin/mysql -u root mysql << EOFupdate user set password = Password('$mysql_root_password') where User = 'root';EOFreset_status=`echo $?`if [ $reset_status = "0" ]; thenprintf "Password reset succesfully. Now killing mysqld softly\n"killall mysqldsleep 10printf "Restarting the actual mysql service\n"/etc/init.d/mysql startprintf "Password successfully reset to '$mysql_root_password'\n"elseprintf "Reset MySQL root password failed!\n"fi

其中有些地方需要自己手工修改，例如：

/usr/bin/mysqld_safe --skip-grant-tables >/dev/null 2>&1 &

在我的电脑中输入命令： whereis mysqld_safe 

结果如下：

mysqld_safe: /usr/bin/mysqld_safe /usr/bin/X11/mysqld_safe /usr/share/man/man1/mysqld_safe.1.gz

所以根据个人情况就修改第31行。

还有一个是第35行，我执行：whereis mysql，结果如下：

mysql: /usr/bin/mysql /etc/mysql /usr/lib/mysql /usr/bin/X11/mysql /usr/include/mysql /usr/share/mysql /usr/share/man/man1/mysql.1.gz

至于MySQL默认字符集的修改如下： 

这里只考虑linux系统，找到/etc/mysql/my.cnf ，使用root权限打开，

做以下改动：

配置文件中添加如下内容：[client]default-character-set=utf8[mysqld]character_set_server=utf8init_connect='SET NAMES utf8'

修改完后，重启mysql的服务，service mysql restart

使用 mysql> SHOW VARIABLES LIKE 'character%';查看，发现数据库编码均已改成utf8。