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sql-server-2008vb.net-2010sqldatatypes

How to retrieve VARBINARY values from SQL Server 2008 using VB.Net


I'm trying to populate a listview with varBinary(max) values. Well, I actually need to write each varBinary into a csv file and the table consists of 100 000 odd rows.

I just don't know how to retrieve the datatype!

    Sub getInformation()
    Try
        If Not String.IsNullOrWhiteSpace(connString) Then
            Using cn As SqlConnection = New SqlConnection(connString)
                cn.Open()
                Using cmd As SqlCommand = New SqlCommand()
                    cmd.Connection = cn
                    Dim qry As String
                    qry = String.Format("SELECT [varBinaryField] FROM [dbX].[dbo].[tableX]")
                    cmd.CommandText = qry
                    cmd.CommandTimeout = 0

                    Using myReader As SqlDataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection)
                        While (myReader.Read())
                            ListView1.Items.Add(myReader.get?WHAT?(0)) 'Help needed here.
                        End While
                    End Using
                End Using
            End Using
        End If
    Catch ex As Exception
        MsgBox(ex.Message)
    End Try
End Sub

Heres an example of one of the varBinary codes :

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


Solution

  •     Using cn As SqlConnection = New SqlConnection("Server=.;Database=test;Trusted_Connection=True;")
            cn.Open()
            Using cmd As SqlCommand = New SqlCommand()
                cmd.Connection = cn
                Dim qry As String
                qry = String.Format("SELECT field FROM test.dbo.test")
                cmd.CommandText = qry
                cmd.CommandTimeout = 0
                Dim oFileStream As System.IO.FileStream
                oFileStream = New System.IO.FileStream("c:\bytes.txt", System.IO.FileMode.Append)
                Using myReader As SqlDataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection)
                    While (myReader.Read())
                        Dim data As Byte() = myReader(0)
                        oFileStream.Write(data, 0, data.Length)
                    End While
                    oFileStream.Close()
                End Using
            End Using
        End Using
    

    UPDATE: here is: another example on VB.NET