EF6 does not commit changes to Database

Question

Hey Guys. 
Actually it looks quite simple, but I won't get it right. 
I try to save changes made to an object from an project-included DB using EntityFramework 6. the changes are correctly updated in the local objects instance and the EnitityEntry - State is set to "modified", but after calling Entities.SaveChanges()
(which does return 1 for one affected row, which is right) does not persist it to the DB, because after Project relaunch the Updated Data is gone. Please can you help me. 
Thanks in advance. 
Thomas
if (!HasEmptyFields())
Constants.ATLAS_ENTITIES.Entry(Selected).State = System.Data.Entity.EntityState.Modified;
else
Constants.ATLAS_ENTITIES.Entry(Selected).State = System.Data.Entity.EntityState.Added;
int result = Constants.ATLAS_ENTITIES.SaveChanges();
//result = 1 after execution which should be right

Answer 1

Hi Stocki44,
According to your description, the issue can be caused by that the setting of the Copy to Output Directory is not configured properly.  I recommend you choose the appropriate option according to the following link. Also you can review this
FAQ to troubleshoot this issue.
How to: Manage Local Data Files in Your Project:
http://msdn.microsoft.com/en-us/library/ms246989.aspx
Thanks,
Lydia Zhang