VirtualHost for subdomain also re-routes traffic to host domain - apache

Question

I'm trying to make it so when someone visits my site at sub.example.com, it sends them to a different folder than someone who visits example.com. Simple, yes? This is the code I use to do it:
NameVirtualHost *:80
<VirtualHost *:80>
DocumentRoot "C:/xampp/htdocs/sub"
ServerName sub.example.com
ServerAlias sub.example.com
</VirtualHost>
I have the DNS for my domain set for a wildcard so that any subdomain still directs to my server.
The problem is, now whenever someone visits example.com or sub.example.com or any subdomain, it shows the content from /htdocs/sub
I only want it to show /htdocs/sub when sub.example.com is visited, how do I do that?
From what I've read my execution seems right, but maybe I've missed one thing that causes this to happen? I've reinstalled xampp to no avail
My main httpd.conf has this line ServerName example.com:80 if this helps

Answer 1

I ended up finding a solution, and to anyone in the future with the same problem, this is what I did:
NameVirtualHost *:80
<VirtualHost *:80>
ServerName www.example.com
ServerAlias example.com
DocumentRoot "C:/xampp/htdocs/"
</VirtualHost>
<VirtualHost *:80>
ServerName sub.example.com
DocumentRoot "C:/xampp/htdocs/sub"
</VirtualHost>
I assume that basically for the VirtualHost to differentiate between sub.example.com and example.com then a VirtualHost first must be defined for example.com before any subdomains can be configured