how to keep a odbc connection open in vb.net - vb.net

Question

I'm trying to connect to a database and keep the connection open for any amount of user activity/queries within the database. Currently I have a connection that opens and closes for any query (save, update, etc...) which requires the logon process to the back-end every time the user saves etc... Is there a way to simply connect and leave the connection open so there won't be a lag time when running the query due to the logon process? This is what I'm using:
Private sConStrFormat As String = "Provider=TDOLEDB;Data Source=TDDEV;Persist Security Info=True;User ID={0};Password={1};Default Database=bcpm_ddbo;Session Mode=ANSI;"
Private Sub cmdsave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdsave.Click
Dim sSQL As String
Dim sConStr As String
Dim user As String
Dim pass As String
user = txtuser.Text
pass = txtpass.Text
Dim UserName As String = user
Dim Password As String = pass
sConStr = String.Format(sConStrFormat, UserName, Password)
Using Con As System.Data.OleDb.OleDbConnection = New System.Data.OleDb.OleDbConnection(sConStr)
Con.Open()
sSQL = "INSERT INTO LTC_FBS (CLM_NUM) VALUES ('" & Me.txtClaim.Text & "')"
Dim cmdins As New System.Data.OleDb.OleDbCommand(sSQL, Con)
cmdins.ExecuteNonQuery()
Con.Close()
End Using
End Sub

Answer 1

.Net automatically maintains a connection pool for you. According to MSDN, when you call Close() on the Connection the framework
releases the connection to the
connection pool, or closes the
connection if connection pooling is
disabled

Answer 2

In vb.net 4.5 do the following:
At the top straight after the class definer put in this line:
Public Shared conn As OdbcConnection
Then, in the subs where you want to use the connection use this line:
If conn Is Nothing Then conn = New OdbcConnection(<your_connection_string>): conn.Open()
Then the New OdbcCommand will use the existing connection without opening a new one. Don't close the connection in your script until you are quite certain you're finished with it (_Shutdown is a good spot and you're good to go.
This also solves problems with MySQL when constantly opening new connections causes the max connections error.

Answer 3

Instead of defining 'con' in the using statement, define it up above as a static variable. When the function is called, you can see if 'Con' has been assined or not. If not, you build your connection string and set Con = New OleDBConnection, and open it. Since it's a static variable, it will retain its value at the next call. Check that it's not nothing, and then use it right away. Make sure you don't call close in the routine or the connection will not remain open.