You can't connect directly to MySQL from Tableau Public, according to this : https://community.tableau.com/docs/DOC-9135#subhead20
Have you tried Tableau Desktop (Professional) yet ? You can download and use for free for 14 days.
If I am having Tableau Desktop, can you explain me how to proceed with such scenario then?
I haven't used mySQL much, but it should work the same as any other RDBMS. You can see how it works here : MySQL
If you have a live connection and update the database, the new data will be visible in Tableau as soon as you run the next query - which could be as simple as changing a filter value.
If you have an extract connection, you will need to refresh the extract to see the changed data.
No, that's only the data window.
To refresh the data you actually have to do something in Tableau to make it requery that database.
Thanks Chris. But I was looking for something totally automatic. That No one do nothing, and all the data gets updated.
OK, so I think you're trying to say this ...
"I want to create a dashboard that automagically refreshes every X minutes to show the new data in the database with no human intervention at all."
You can do all this on demo software - a demo version of Tableau Desktop and a demo version of Tableau Server BUT if this automatically refreshing webpage is displayed on a screen where multiple people can see it then you must buy a core license of Tableau Server to enable "guest access". Talk to your local Tableau Account Manager about these options.