If you are asking then I am guessing you don't have the skill level to do it as it will require you to export and import tables.
Short answer, you will lose all the content.
Also, you get better help when you post the topic with the correct title of the problem, not bug data; you posted another one with bug data.
Not to be rude, but your English is lacking; so please; as was suggested before, post in your native language and we will try to translate.
So, post a new topic with a clear title of the problem with as much useful information as possible and we will see if we can help you.