>
> Hello Kurt
>
> Thanks for the information.  It helped us a lot.  Now I'm sort of
> curious about the Web Servers and Database Server.  Could you explain a
> little bit
> about How they are used?, Do you set them up on a dedicated Server or a
> desktop machine?, and how long do you think either server takes to
> construct?
>
> Sincerely Joanne

Without a web server, a web page can't be fetched across the internet, so
your web page needs to be on a web server.   The web server simply responds
to requests for web pages.  If you already have a web page, then it is
on a machine that is running a web server.

You would not want to construct a web server.  That would be a lot of work.
You'd need to buy one or find a freeware version.  Sometimes, if you can
connect to a large server machine or mainframe, it will have one on it.
For example, we have a mainframe for our department, and it has a web
server, but it uses UNIX as the operating system, and I didn't  know how
to obtain drivers for MS Access for UNIX, so we obtained our own web    
server.

We installed Microsoft's web server IIs, which (I believe) came with NT
Workstation.  I've tried several web servers, and all of them are very
easy to use.

Web servers can be run on any machine connect to the internet.  If you're
using Windows '95, the server will always be running, so it can be any
machine.  If multiple users can get on the machine, the only problem is
if one of them shuts down the web server.  If they restart the machine, the
web server will come back up automatically.  On NT, you'd need
administrator privileges on a particular machine to set up a web server
and have it run for all users who logged on.

A database server is similar to a web server:  you connect to it, send it
requests, and it returns data.  However, instead of web pages, it returns
database data.

For the database server we wrote, we just send it a string, which is just an
SQL query, and the server queries the database and returns the results(as
strings).  We wrote a client-side program which parses the strings.   

Some people use CGI to query databases.  In that case, the web server itself
calls a program you (or someone) has written which queries the database
and returns the results to the web server, which passes the data back to
you.  The advantage of this is that you don't need a database server, just
a program to query the database.  However, you still need to parse the
CGI query and any results sent back.  I gave a link to an example of how to
query a database using CGI on my web page.

One reason we didn't use CGI is that we could not find examples of CGI
programs written in Java.  There are particular problems writing CGI
programs in Java.  I recently found a URL discussing that issue which I
can send if you like.

However, you can still write a CGI progam in C (or whatever language) and
CALL it from an applet.  In fact, that is the method described in the article
on my web page.

A database server may or may not require a dedicated machine.  In the case
of our db server, we use a dedicated machine, because we are running it
on NT.  On NT, if you "log in as a different user", our db server goes    
down.  You can get around this by installing your db server as an NT "Service".
Even on '95, our db server would be a problem to run on machines with multiple
users.  It's output window is just a DOS window.  Clicking the close box
shuts down the server.  Again, that's only an issue if you expect continual
usage of your applet.

I suspect it's likely that Cafe allows you the option of leaving the db Server
running at all times on '95.  Other users can shut it down, but they probably
won't even be aware it is running, since you can hide the output window.
With Cafe, the issue is the same for both the db and web servers: you just need
someplace to install it that is connected to the internet.   You don't need
to reserve a special machine, unless you're really worried about people
shutting down the servers.

The db Server must run on the same machine as the web server.  That's because
the applet security restrictions only allow an applet to connect back to
the server from which it was loaded.  (It may be that jdk1.1.5 allows you to
get around this--I haven't looked into that.)

Hope this was helpful,         

--Kurt B.