Permissions on new mdf file - sql-server

Question

I'm trying to write a program to allow a non-privileged technically naive user to create a new SQL Server database and receive it in the form of a .mdf file. I understand that .mdf files are not really supposed to be treated like database backups, but I need to do it this way to maintain compatibility with existing commercial software that works like this.
I'm using Visual Studio 2013 and SQL Server 2014, though I would like the program to be able to work with versions of SQL Server going back at least to 2008.
What I find is that I can't copy the .mdf file created by
CREATE DATABASE XXXXX on
(NAME=<name>,FILENAME=<filename>')
because it ends up belonging (I think) to MSSQL$SQLEXPRESS. The reason I say 'I think' is that when I go to the file properties and accept Administrator privileges to view the owner, it tells me 'Unable to display current owner.' I can transfer ownership of the file, but only using Administrator privileges.
So it seems that I cannot copy the .MDF file without Administrator privileges, which seems fairly ridiculous given that I was able to create the file without those privileges. I've tried creating the file in a folder located under my user's App_Data folder and with full access for everyone to subfolders and files, but that didn't help.
Can anyone suggest me what I can do (programatically) to make this file available to a non-privileged user?
Many thanks for your help.

Answer 1

Try following script before trying to copy mdf file:
USE [master]
GO
EXEC master.dbo.sp_detach_db #dbname = N'DatabaseName';
GO
It will detach Database from SQL Server and you can treat it's files as regular files within a system.
After copying you'd have to re-attach the database by "sp_attach_db".
Be aware that during that period database won't be visible by SQL Server.
USE [master]
GO
EXEC master.dbo.sp_attach_db #dbname = N'DatabaseName'
, #filename1 = 'C:\Data\Datfile.mdf';
, #filename2 = 'C:\Data\Logfile.ldf';
GO

Answer 2

First get location of data files into a variable, so that you can easly move from there after you detach.
select a.filename from sys.sysfiles a inner join sys.master_files b on a.fileid=b.file_id
where b.database_id=db_id('DB_NAME')
Verify if there is any open session with the database.
select spid from sysprocesses where dbid=db_id('DB_NAME')
Kill All the sessions using [kill spid]
Then Detach your database
USE [master]
GO
EXEC master.dbo.sp_detach_db 'DB_NAME';
Now you can move the database from the source holded in the variable to desired destination.
Now if you want to attach the database on other server.
If you moved both .ldf and .mdf to same directory
USE [master]
GO
EXEC master.dbo.sp_attach_db #dbname = 'DB_NAME', #filename1 = 'C:\Data\Datfile.mdf';
If you moved .ldf and .mdf to seperate directory.
Use the script suggested by Mr. Slava Murygin here to attach database.
Thanks