之前在電腦里安裝了MySQL57之后，一直沒用，卻忘記了root密碼，
在網上找了一些資料修改root密碼，卻一直出錯。直到試到這個：
用管理員權限打開CMD
CD C:Program FilesMySQLMySQL Server 5.7bin
net stop mysql57
mysqld --skip-grant-tables
再另外打開一個管理員權限的CMD
CD C:Program FilesMySQLMySQL Server 5.7bin
mysql
mysql> use mysql
mysql> update mysql.user set authentication_string=PASSWORD('yourpassword') where user='root';
mysql> flush privileges;
mysql> quit Bye
OK，用新密碼登陸即可：
C:Program FilesMySQLMySQL Server 5.7bin>mysql -u root -p Enter password: ************ Welcome to the MySQL monitor. Commands end with ; or g. Your MySQL connection id is 10 Server version: 5.7.15 MySQL Community Server (GPL)
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mysql>
