how do you delete purchase history
u cannot permanently delete your purchase history but u can hide them if u want to. Go to App store icon on the iphone then go to updates on down, right hand side corner on the iphone screen. Now u are able to see the list of applications u have downloaded or installed.
Just swipe or sweep u r finger to right hand side or left hand side (any side just swipe very gently) then u will get a red button showing hide option. just tap it. That's it. Now if u give u r iphone to anyone they cannot see what u hide. but if they got u r apple ID & password and if they connect u r iphone to itunes they can still see what u r hiding.
u can find this hiding/unhiding option on itunes aswell. open itunes software & click on itunes store option on rihgt side of u r screen and then login to u r account (click on right side, top, corner sigin button). on the account information page u will see all the details of u r accounts, purchases, hiding purchases etc...
best of luck,