使用 MySql 遇到的问题_system.invalidoperationexception: an exception has

1. Entity Framework Core 连接 MySql

连接数据库出现以下错误:

System.InvalidOperationException: An exception has been raised that is likely due to a transient failure. Consider enabling transient error resiliency by adding 'EnableRetryOnFailure()' to the 'UseMySql' call.

版本问题，使用自动检测版本方法

var connectionString = configuration.GetConnectionString(connectStr);
services.AddDbContext<T>(options =>
{
   options.UseMySql(connectionString, ServerVersion.AutoDetect(connectionString));
});

2. 认证问题

MySql 8.0 默认使用 caching_sha2_password 插件认证，解决方法：

. https://mysqlconnector.net/troubleshooting/retrieval-public-key/#:~:text=To%20retrieve%20the%20server%E2%80%99s%20public%20key%2C%20connect%20securely,to%20the%20connection%20string%3B%20this%20is%20potentially%20insecure.

. 修改认证

ALTER USER '用户名'@'%' IDENTIFIED WITH mysql_native_password BY '密码';
FLUSH PRIVILEGES;