Error opening connection to SQL CE file on test machine

I'm testing my application on a non-administrator windows 7 account. The application is installed into program files. This includes the .sdf file I need to read from. I've got the connection string marked as read only and set the temp path to my documents. This is the error that it spits out when I try to do connection.Open()

Internal error: Cannot open the shared memory region

I've got the connection开发者_StackOverflow社区 string defined in app.config, but I'm modifying it before I start using the connection. This part is in app.config Data Source=|DataDirectory|\DB.sdf;Password=password;

And then I modify it like so:

    connection = new SqlCeConnection(connectionString +
 ";Mode=Read Only; Temp Path=" + Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments));

This works on my developer machine (obviously) since its running from outside of a read-only directory. But even when I manually mark the .sdf file as read-only it still works, and successfully creates the temporary db file in the correct folder. However, on the test machine everything is located in a read-only program files folder, and it doesn't work.

The main goal of this problem is trying to make sure my program doesn't have to be ran as an administrator, and I would like to keep from moving the main copy of the db file from outside of the installation directory.

Let me know if I need to explain anything else. Thanks

I'm using a sql ce database too and had the same problems. my solution was to create the database in a subfolder in Environment.SpecialFolder.CommonApplicationData. If only one user will use it you can create it in Environment.SpecialFolder.ApplicationData. But here you don't need admin rights.

Another point is your connection string in your app.config. If you'll modify it in your program like me, it must be located in such a 'non-admin-right-needed' folder too. I have a static app.config in my app-folder in program files, but a second one with the connection string in Environment.SpecialFolder.LocalApplicationData (this is 'username\AppData\Local' in Win7). And I protect my connectionstring with DataProtectionConfigurationProvider encryption, so no one can read the data base password.

This is how you can map your second app.config to your app:

string ConfigPathString = @"{0}\MyApp\MyApp.config";
string ConfigPath = String.Format( ConfigPathString, System.Environment.GetFolderPath( Environment.SpecialFolder.LocalApplicationData ) );

ExeConfigurationFileMap fileMap = new ExeConfigurationFileMap();
fileMap.ExeConfigFilename = ConfigPath;
Configuration Config = ConfigurationManager.OpenMappedExeConfiguration( fileMap, ConfigurationUserLevel.None );

string myConnectionString = ConnectionStrings.ConnectionStrings["MyConnectionStringKey"].ConnectionString;

Like Calgary already mentioned in his comments you can't really open the file directly in the programs folder due to the restrictions of Windows 7 to non-admins. But due to the fact that you don't want to write anything into it, why don't you simply copy at startup the file into Environment.SpecialFolder.ApplicationData?

When your program starts up simply copy the file out of the programs folder into a proper location, use it as you like and delete it on application exit. So you don't leave any fragments (except the application would crash).

Just to be sure for the last scenario, you could add an additional delete operation to the setup deinstallation routine. So if the application will be removed and it crashed at the last start the setup will remove the trash, leaving the machine as before the installation of the software.