MySQL80修改密码

mysql> update user set password=password('123') where user='root' and host='localhost';
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '('123') where user='root' and host='localhost'' at line 1
mysql> alter user root@localhosten identified by'123456';
ERROR 1396 (HY000): Operation ALTER USER failed for 'root'@'localhosten'
mysql> alter user root identified by'123456';
ERROR 1396 (HY000): Operation ALTER USER failed for 'root'@'%'
mysql> alter user user() identified by "123456";
ERROR 1396 (HY000): Operation ALTER USER failed for 'ODBC'@'skip-grants host'
mysql> ALTER USER'root'@'%'IDENTIFIED WITH mysql_native_password BY 'password';
ERROR 1396 (HY000): Operation ALTER USER failed for 'root'@'%'
mysql> select user from user;
ERROR 1046 (3D000): No database selected
mysql> use mysql;
Database changed
mysql> select user from user;
+------------------+
| user             |
+------------------+
| mysql.infoschema |
| mysql.session    |
| mysql.sys        |
| root             |
+------------------+
4 rows in set (0.00 sec)

通过跳过密码的方式进入了MySQL，然后试图修改密码，在修改MySQL密码过程中遇到了很多次报1064错，但最终并不清楚这个错是怎么来的，换了很多种改密码的命令行，但是都不行，后来直接重新建了一个：

mysql> drop user root@localhost;
Query OK, 0 rows affected (0.24 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.12 sec)

mysql> create user root@localhost identified by '123456';
Query OK, 0 rows affected (0.24 sec)

mysql> select user,host from user;
+------------------+-----------+
| user             | host      |
+------------------+-----------+
| mysql.infoschema | localhost |
| mysql.session    | localhost |
| mysql.sys        | localhost |
| root             | localhost |
+------------------+-----------+
4 rows in set (0.00 sec)