Im an experienced database+software designer and developer,
but, unfortunately, anything to do with web-programming and
web-systems designs is still a pretty new area to me...
(been working mostly with "legacy" environments the last 10 years)

So I am writing this, hoping to get some useful advise and feedback...

I have done some pretty trivial, small websites with html/PHP,
and now starting a bit more advanced one, where I will need SQL
database-support, and will probably go for MySQL.

Of course, I have read some elemantary tutorials and articles on the web,
but still wonder how PHP is actually being used in practice when
creating bigger web-sites...

Is PHP-scripts usually handcoded?
Like... you just make up a database, then a number of tables you think will do,
and finally (what I am most concerned about) a multiplicity of different
PHP script-files in an ad-hoc fashion?
(I hope not, since it seems that this will quite soon produce a pretty
diffcult-to-maintain-and-grasp mess of the whole system)

So what I would like to learn, is what nice (preferrably free/open-source)
tools for design and project-management are available?

My idea is that you would like to have some IDE application, something
like VB or Delphi or VC++, where you design your webpages and
forms in a graphical manner, and you can code "event" pieces of code
that will react to clicks, buttons and user-actions like
in the traditional IDE:s.
And then there is some "compiler" or rather that do all the boring routine-work
of converting your design to html/PHP code.
The page-designs would also be based on "templates", of course,
so its flexible to modify if you want to change the look-and-feel
of your whole site.

Ideally, I would also prefer that the whole website-design
would be stored in a separate, fixed set of tables in the database,
rather than in a zillion different script-files, CSS-sheets, etc.

I can also envision a design where, even if the website contains
a huge number of pages and different functions,
there would actually only be a single PHP-script "index.php"
and all sub-pages are generated on-the-fly, from arguments
in the URL, i.e. all URLs simply looking like:

index.php?pageid=1
index.php?pageid=2
...
index.php?pageid=productlist
index.php?pageid=registration
index.php?pageid=loginform
index.php?pageid=contactform

etc...

The index.php startfile might only look something like:

<html>
<php?
include("lib.php");
main();
?>
</html>

Then all pages would be generated on-the-fly by the main() function
(defined in "lib.php", along with a host of useful subroutines),
and driven by the URL-parameter 'pageid' and the overall site-design
somehow stored in the database.

All design-work you did in the IDE (graphical, code-snippets, etc)
would then actually be stored in the DB, and the PHP script-files
could then be a quite static PHP-implementation of an "engine"
reading the DB-content and outputting the HTML-code and pages.

So... could you please give me a short brief/hints/links to what
IDEs and/or other free tools, along those lines, that already exist
or what are commonly used for PHP/MySQL in real-world development.

Thanks,