LBD Lock File Remains After Connection Closed

I'm using MDB database files and I've noticed that if I run many different SQL statements during a single connection, the LDB file doesn't get deleted when the connection is closed. When the program is closed, the LDB file is then deleted.

I've made a simple program to illustrate this problem, this is a bit of a pointless program, but it shows the problem:

Code:

---

        Dim con As OleDbConnection = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0 ;Data Source=test.mdb")

        con.Open()

        'changing this loop to something higher (such as 100) causes the problem
        For counter As Integer = 0 To 10
                Dim query As String = "SELECT * FROM MyTable"

                Dim cmd As OleDbCommand = New OleDbCommand(query, con)
                Dim dr As OleDbDataReader = cmd.ExecuteReader
        Next

        con.Close()

---

I have a loop setup in the above that just repeatedly does the same thing 10 times. Running this loop, the LDB file doesn't remain at the end of the routine. If I change the loop to run 100 times, the LDB file will remain until I close the program.

I suspect that when the program calls con.close(), the MDB file is still being used to so the LDB file isn't deleted. That's just my best guess though. Not sure how to fix that.

Anyone know the cause of this and a possible solution?

Alright, after a lot of trial and error I finally figured out what I was doing wrong in the above example. I needed to call dr.close(). After adding that, I'm not having any problems. I even increased the loop to 1,000,000 to test. It took a little while to run, but the ldb file was successfully deleted at the end.