I created a windows application with C# 2010, and I'm using SQL Server Compact Edition 3.5.
I'm also using a DataSet to change the DB with a TabelAdapter, and a bindingnavigat to add/edit/delete.
The problem is : I can do all these commands during the execution, I can see the rows added and edited in a DataGridView, but when I go to server databases solution and verify my data, no event had been done !! no rows added !
Your database may be copied from somewhere/Projectname to somewhere/Projectname/bin/Debug/. Check properties on database file in your project tree. There should be "Copy to Output Directory" property that is set to "always copy". If there is "always copy" - your application is working on database copy.
Read about "Copy to Output Directory" in help.
There is more detailed explanation of that problem: link to MSDN social
(question about VB, but it applies to C# too)
来源：https://stackoverflow.com/questions/12758283/changes-are-not-saved-in-sql-server-compact-3-5-database