gistfile1.txt

' Build a Connection to use
Using connection = New OleDbConnection("{your-connection-string}")
    ' Open your connection
    connection.Open()
    ' Build your query (using parameters)
    Dim query = "UPDATE tb_kamar SET no_ktp = NULL WHERE no_kamar = ?"
    ' Build a command to execute
    Using command = New OleDbCommand(query, connection)
        ' Add your parameters
        command.Parameters.AddWithValue("@sed", cbnokam.Text)
        ' Execute your update
        command.ExecuteNonQuery()
    End Using
End Using