Suggestion [3,General]: 找不到命令 /mysqld.exe，但它确实存在于当前位置。默认情况下，Windows PowerShell 不会从当前位置加
载命令。如果信任此命令，请改为键入“.\/mysqld.exe”。有关详细信息，请参阅 "get-help about_Command_Precedence"。
PS D:\Development\DataBase\mysql-8.0.16-winx64\bin>
PS D:\Development\DataBase\mysql-8.0.16-winx64\bin>
PS D:\Development\DataBase\mysql-8.0.16-winx64\bin>
PS D:\Development\DataBase\mysql-8.0.16-winx64\bin> ./mysqld --initialize --console
2019-07-26T13:04:40.868710Z 0 [System] [MY-013169] [Server] D:\Development\DataBase\mysql-8.0.16-winx64\bin\mysqld.exe (
mysqld 8.0.16) initializing of server in progress as process 11000
2019-07-26T13:04:40.875362Z 0 [Warning] [MY-013242] [Server] --character-set-server: 'utf8' is currently an alias for th
e character set UTF8MB3, but will be an alias for UTF8MB4 in a future release. Please consider using UTF8MB4 in order to
be unambiguous.
2019-07-26T13:05:01.278758Z 5 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: KR+jt(_k
q1G7
2019-07-26T13:05:08.823938Z 0 [System] [MY-013170] [Server] D:\Development\DataBase\mysql-8.0.16-winx64\bin\mysqld.exe (
mysqld 8.0.16) initializing of server has completed
PS D:\Development\DataBase\mysql-8.0.16-winx64\bin>

PS D:\Development\DataBase\mysql-8.0.16-winx64\bin> ./mysqld install
Service successfully installed.
PS D:\Development\DataBase\mysql-8.0.16-winx64\bin>
PS D:\Development\database\mysql-8.0.16-winx64\bin> ./mysql -u root -p
Enter password: ****
ERROR 2003 (HY000): Can't connect to MySQL server on 'localhost' (10061)
PS D:\Development\database\mysql-8.0.16-winx64\bin> net start mysql
MySQL 服务正在启动 .
MySQL 服务已经启动成功。

PS D:\Development\database\mysql-8.0.16-winx64\bin> ./mysql -u root -p
Enter password: ****
Welcome to the MySQL monitor.Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.16

Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.

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>

参考其他博主文章，找到解决方法：
从8.0.11版本起，不再像mysql5.7及以前版本那样，设置用户密码时默认的验证方式为caching_sha2_password，如果发现升级mysql8.0.11后原有的程序不能连接mysql，可迅速在mysql command line client客户端用下面的命令设置成mysql5.7及以前版本的密码验证方式，同时MYSQL8.0.11下修改密码的方式与原先也不大一样，原先的部分修改密码的命令在mysql8.0.11下不能使用。
use mysql
ALTER USER ‘root’@’localhost’ IDENTIFIED WITH mysql_native_password BY ‘你的密码’;
FLUSH PRIVILEGES;

该caching_sha2_password和 sha256_password认证插件提供比mysql_native_password插件更安全的密码加密 ，并 caching_sha2_password提供了比更好的性能sha256_password。由于这些优越的安全性和性能特性 caching_sha2_password它是MySQL 8.0首选的身份验证插件，而且也是默认的身份验证插件而不是 mysql_native_password。此更改会影响服务器和libmysqlclient 客户端库；目前来说和经常使用的客户端软件兼容性不好。