mysql> update user set password=password(“新密码”) where user=”用户名”;
执行后报错 　ERROR 1054(42S22) Unknown column 'password' in ‘field list’

错误的原因是 5.7版本下的mysql数据库下已经没有password这个字段了，password字段改成了authentication_string

所以请使用一下命令：

mysql -u root -p

Enter password: **
**Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 12
Server version: 5.7.18-log MySQL Community Server (GPL)**
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Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> use mysql;
Database changed
mysql> select User from user; #此处为查询用户命令
--------- | User |
--------- | * | | mysql.sys | | root |
**---------**
rows in set (0.00 sec)
mysql> update user set password=password("*") where user="*"; #修改密码报错
ERROR 1054 (42S22): Unknown column 'password' in 'field list'
mysql> update mysql.user set authentication_string=password('*') where user='*'; #修改密码成功
Query OK, 1 row affected, 1 warning (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 1

mysql> flush privileges; #立即生效
Query OK, 0 rows affected (0.00 sec)

mysql> quit
Bye

n>mysql -u * -p #以该用户登录成功.
Enter password:
…………………………
mysql>