sql exception when transferring project from usb to c:\

Question

I'm working on a C# windows program with Visual Studio 2008. Usually, I work from school, directly on my usb drive. But when I copy the folder on my hard drive at home, an sql exception is unhandled whenever I try to write to the database. it is unhandled at the conn.Open(); line. here's the exception unhandled

Database 'L:\system\project\the_project\the_project\bin\Debug\PatientMonitoringDatabase.mdf' already exists. Choose a different database name. Cannot attach the file 'C:\Documents and Settings\Administrator\My Documents\system\project\the_project\the_project\bin\Debug\PatientMonitoringDatabase.mdf' as database 'PatientMonitoringDatabase'.

it's weird, because my connection string says |DataDirectory|, so it should work on any drive... here's my connection string:

string connStr = "Data Source=.\\SQLEXPRESS;AttachDbFilename=|DataDirectory|\\PatientMonitoringDatabase.mdf; " +
                "Initial Catalog=PatientMonitoringDatabase; " +
                "Integrated Security=True";

Answer 1

I think the complaint here is that your local SQL Server Express install already has a PatientMonitoringDatabase attached and running.

Connect to localhost with SQL Server Management Studio Express (if not installed, download here) and remove/detach the existing PatientMonitoringDatabase database. Whether it's a persistent database or only active within a running application, you can't have 2 databases with the same name at the same time attached to a SQL Server instance.