Hello @Dinh-1274, welcome to the community and thank you for your question! Integrations such as what you described have been commonly requested since launch, and we've made some progress on that front. I wanted to make sure you were aware of the recent related announcement, which is that you can now integrate data with both AppFlow and Zapier. Integrate Data with Zapier and Amazon AppFlow. This may help particularly on the RDS integration, but it also opens opportunities to integrate with hundreds of other apps as well, with a more user-friendly / less-coding interface.
As for Quicksight, we do not have any direct integrations today (besides the API method), however, I am taking note of this and will report it back to our product management team.
Lastly, on a related note, depending on how sophisticated your charting use case(s) are, there is a Honeycode bar chart feature that is coming soon, so stay tuned for that!
Hope this all helps.