[HOW] When <a > click automatically send value 1 or 0 to db

[eluser]johnpeace[/eluser]
What URL does that link have as an href?

You could do something like this:
- depending on the value in the DB (0 or 1) set the value in the link to the opposite, so
- if the DB has a 1, the link will have a 0 and the inverse is also true

So, the value being passed in the URL (you know how URLs route to controllers with parameters, right?) is always the inverse of what was in the DB at page load time.