Do you have SAML Database Configuration Resolver for MySQL database ?
The SamlDatabaseConfigurationResolver that we include stores the SAML configuration in an Entity Framework database. This could use MySQL.
We don’t have a SAML configuration resolver for MySQL but you could implement the ISamlConfigurationResolver interface and retrieve SAML configuration from a custom MySQL database.
The ExampleServiceProvider project includes a ConfigurationExamples class with an ISamlConfigurationResolver implementation that uses hardcoded values for simplicity. You could use this as a template with your implementation retrieving the configuration from the database.