If it comes to Greater Poland Uprising - after-uprising combat reports say about 1714 dead, during the past 85 - 90 years due to research of different historians this number was of course constantly growing - modern data (2008) says about 2289 dead.
Of course this is about Polish losses - both combat and non-combat losses. There are 2284 men and 5 women among them. Over 130 surnames are unknown. 1100 out of these 2289 dead are confirmed to be KIA, almost 200 - DoW, over 110 - MIA, almost 200 - DoS, 30 - drowned and 1 - drunken to death.

The exact cause of death of the remaining ca. 650 is unclear.
In February of 1919 forces of the Greater Poland Uprising numbered over 30,000 soldiers in frontline units equipped with over 25,000 rifles, 250 machine guns, 50,000 hand grenades and over 80 artillery guns. There were 2,000,000 rounds of ammo.
Soon after the end of the successful uprising (in late April / early May of 1919) Armia Wielkopolska (Army of Greater Poland) numbered yet some 70,000 soldiers and had got 12 rifle regiments, 2 cavalry brigades, 3 artillery regiments and strong Air Force (4 battalions), communication units, sappers and medical service. A lot of equipment was captured on Germans.
On 28 August of 1919 the Army of Greater Poland was incorporated into the structures of Wojsko Polskie (Polish Army).
There is probably no any data concerning German losses in the uprising, maybe except some estimations.
Soldiers of Greater Poland in trenches, January of 1919:

There are words which carry the presage of defeat. Defence is such a word. What is the result of an even victorious defence? The next attempt of imposing it to that weaker, defender. The attacker, despite temporary setback, feels the master of situation.