今天遇到此问题的任何人都应在6:05左右观看此***视频:

Anyone encountering this issue today should check out this *** video at around 6:05:

AWS RDS MySQL数据库设置|逐步教程.

简而言之，您必须创建一个新的入站安全规则以允许外部连接.

In a nutshell, you have to create a new inbound security rule to allow an external connection.