I’ve just upgraded a Debian server from Wheezy to Jessie with these steps:

# apt-get update && apt-get upgrade && apt-get dist-upgrade
# dpkg --audit && dpkg --get-selections | grep hold
# vim /etc/apt/sources.list
[add these list - for Indonesian user]
deb http://kambing.ui.ac.id/debian/ jessie main contrib non-free
deb-src http://kambing.ui.ac.id/debian/ jessie main contrib non-free
deb http://kambing.ui.ac.id/debian/ jessie-updates main contrib non-free
deb-src http://kambing.ui.ac.id/debian/ jessie-updates main contrib non-free
deb http://security.debian.org/ jessie/updates main contrib non-free
deb-src http://security.debian.org/ jessie/updates main contrib non-free
# apt-get update && apt-get upgrade && apt-get dist-upgrade
# more /etc/debian_version && more /etc/os-release
# reboot

Add apache-mysql-php:

# apt-get install mysql-server mysql-client
# apt-get install apache2 apache2-doc
# apt-get install php5 libapache2-mod-php5 php5-mysql
# service apache2 restart

Source:
– https://www.howtoforge.com/tutorial/how-to-upgrade-debian-wheezy-to-jessie-stable-release/