This would depend on if you have a LIVE connection or your dashboard is based on extracts.
Live connections would do what you are desiring but could have performance issues depending on the size of the data sets you are looking to display. If your data size gets to be large enough to affect performance, then it is highly recommended to implement a setup that utilizes extracts refreshed on a schedule (if possible).
My issue are now the data don't update automatically not even in Tableau, to get the rows updated in the dataset from MySQL server cloud I have to do it manually via Tableau menu Data -> Tableau Data Server -> Refresh from source then it will update the rows and then it also update the dashboard on Table Online.
I wanna tableau update the rows from the data source automatically. Is that possible? Because the MySQL dataset update the rows every hour. So I want Tableau also update the rows from source to.
What kind of poor support service is this company? it's a shame that none one from the staff even answer on a important questions.
I've been working on a Snowflake database that I update in the background, so I know this works.
In my scenario, I'm using a published data source on Tableau Online but the key is that the connection is LIVE - what is your connection type ?
I then use that published data source in a workbook and publish that as well. So now the published workbook is connected to a published data source. This isn't the only way to make it work, but it's preferred if you have many users creating workbooks from the same source.
OK, now I switch over to Snowflake (or in your example MySQL), issue a few DML commands, check that the changes have taken affect.
OK, now I switch back to Tableau and refresh (when you have the dashboard loaded, you see this toolbar):
and press Refresh.
You have to do this using Tableau Online because it usually caches the data a bit.
Now that's the guaranteed way it works. If you're still facing problems, please explain your process and structure and (hopefully) examples of what you've tried and were not successful.