Install Debian on ONE partition

Debian (or any other Linux distribution) will work without swap partition - just don't create one during installation. You can use swap file instead of partition. The swap file can be prepared by the following example commands:

sudo fallocate -l 512MB /swapfile

sudo mkswap /swapfile

The first one creates a 512 MB file, the second one format it as swap file system. After creating the swap file, include it to the /etc/fstab by adding a line like this:

/swapfile none swap sw 0 0

That's it! After reboot your system will use /swapfile as swap area.

Actually if you just leave an unallocated space and 3 primary partitions(1 media 1windows system and 1 windows boot) and then try to install debian and choose guided mode(use 1st largest free space) then it will automatically create 2 logical volumes(1 swap and 1 where all your system files and home folder resides) within an extended primary partition. So that means debian or Ubuntu for that matter doesn't need 2 different primary partitions and can have the 2 volumes in an extended partition. Even if you don't choose guided mode you can manually do this but in guided mode you don't have to do any partitioning or formatting by yourself.