officelink,
Firstly in terms of MySQL being free, for most purposes this is the case and will be in yours. Like most open source providers AB the owners of MySQL get their money via support fees so even though it seems odd that they should "give it away" they can and do make money.
As for your main questions, you will need some sort of web hosting account which has MySQL support, this is easily available but you won't get this with any 'free' hosting account you may have.
In terms of loading once you have your web hosting account there will most likely be a phpMyAdmin interface in your web account control panel which will come as part of your hosting account. It's a good idea to create scripts and run those into phpMyAdmin rather than updating directly as you can just run these scripts against the web hosts MySQL database. I'm not sure if phpMyAdmin has an export command so that you can export and then import the database.
As for your input text field question, the data will be updated on the remote server.
Andrew Gilfrin
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http://gilfster.blogspot.com
My MySQL related Blog
http://www.mysqldevelopment.com
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