SQL Server Express error when using NUnit

This question is for someone experienced with both SQL Server Express and NUnit. I think the answer might be simple, but I would like to understand what is going on and how to prevent it. I have a test class with a TestFixtureSetUp section that calls a method to drop and re-build my database from scratch, including tables for the Membership and Roles provider. This code works fine. After TestFixtureSetUp runs, I have a test to verify that there are 3 records in the Membership database which were added when the database was re-built. The code looks like this:

[Test]

public void MembershipUsersTest()

{

int expectedNumberOfUsers = 3;

MembershipUserCollection users = System.Web.Security.Membership.GetAllUsers();

Assert.AreEqual(expectedNumberOfUsers, users.Count);

}

When this test runs along with the TextFixtureSetUp code, I get this error:

System.Data.SqlClient.SqlException : Cannot open user default database. Login failed. Login failed for user 'TERRY-COMPUTER\Terry'.

However, if I re-run this test but block the TestFixtureSetUp code that re-builds the database, the test passes fine.

I'm guessing it's just a simple matter of NUnit somehow locking access to the database when the database is rebuilt, but I am not understanding why this is happening. My code for re-generating the database uses a "using" construct, so the connnections should be closing properly.

using (SqlConnection conn = new SqlConnection(connectionString))

{

FileInfo file = new FileInfo(fullScriptPath);

string script = file.OpenText().ReadToEnd();

Server server = new Server(new ServerConnection(conn));

server.ConnectionContext.ExecuteNonQuery(script);

}

Any insights into why I am getting this error and how I can avoid it and still run my Membership test right after I re-build the db

One additional piece of information that might be important. The code for rebuilding the databases uses the following connection string:

@"Data Source=.\SQLExpress;Integrated Security=True"

Whereas the Membership provider uses the following connection string which has a hard-coded path to the database:

"Data Source=.\SQLExpress;Integrated Security=True;User Instance=True;AttachDBFilename=C:\MyApps\MyAppsWeb\App_Data\MyApp.mdf"

Again, this MembershipUsersTest runs successfully if I comment out the code that re-builds the database. I¡¯m not clear why the code to rebuild the database would lock up the database if I have wrapped that code in a "using" construct (ensuring that the connections close). Based on this error however, it seems like NUnit is somehow keeping a link to this database. Any insights would be appreciated.

Thanks Jens.

There are really only 2 things going on in my test code. I just re-create my database and tables (using the "using" construct as shown above) and then test the resulting Membership table to confirm that it has 3 users. When I run the test, the database and tables are rebuilt successfully, but the Membership test fails and gives me the error I listed in my last post. But if I comment out the TestFixtureSetUp code that re-builds the database, and then re-run the test, then the Membership test passes.

This makes me think that the only possibility is that NUnit is holding on to the process when I include the rebuild script in my test fixture. But I don't know why this would be if I have wrapped that rebuild code in a "using" statement.

Any insights would be appreciated.

Terry