Is there any scientific data showing one can learn while sleeping?
I don't think that it is possible to learn new facts while sleeping, but it is certainly possible to reactivate certain memories during sleep and thereby affect the probability of those memories being retained. 

In one study, participants learned a visuospatial task while smelling an odour. They were better at remembering how to perform the task if they were subsequently exposed to the same odour during sleep.


  Reactivating Memories during Sleep by Odors: Odor Specificity and
  Associated Changes in Sleep Oscillations, Julia S. Rihm,  Susanne
  Diekelmann,  Jan Born and  Björn Rasch
  https://www.mitpressjournals.org/doi/abs/10.1162/jocn_a_


In another study, participants had to learn spatial locations for some objects and a sound associated with each object. The sounds associated with some of these objects were played back to them during sleep. Upon awakening, they were better at recalling the locations of objects whose sounds they had heard during sleep.


  Strengthening Individual Memories by Reactivating Them During Sleep,
  John D. Rudoy, Joel L. Voss, Carmen E. Westerberg, Ken A. Paller
  https://science.sciencemag.org/content/326/5956/1079


In another study, participants remembered melodies better if they later heard those melodies during sleep.


  Cued memory reactivation during sleep influences skill learning James
  W Antony, Eric W Gobel, Justin K O'Hare,  Paul J Reber&amp; Ken A Paller
  https://www.nature.com/articles/nn.3152