example testing vb.net

-- module
Imports System.Data
Imports System.Data.SqlClient
Imports System.Data.OleDb
'Public con As New SqlConnection("Data Source=SIPPVMNAV01;Initial Catalog=zTech_Temp_Pen_20066;Integrated Security=True")

sample module in vb.net

-- module
Imports System.Data
Imports System.Data.SqlClient
Imports System.Data.OleDb
'Public con As New SqlConnection("Data Source=SIPPVMNAV01;Initial

load combobox | combo box

========== load combobox | combo box
 Sub load_combobox()
        Try
            If (con.State = ConnectionState.Open) Then
                con.Close()
            End If
            con.Open()

code add to database

=============== code add to database
  Try
            If (con.State = ConnectionState.Open) Then
                con.Close()
            End If
            cmd.CommandType = System.Data.CommandType.Text

code click on listview to show data in textbox

====================== code click on listview to show data in textbox
  If ListView1.SelectedItems.Count > 0 Then
            txtCode.Text = ListView1.Items(ListView1.SelectedIndices(0)).Text
            txtModel.Text = ListView1.Items(ListView1.SelectedIndices(0)).SubItems(1).Text
            txtYear.Text = ListView1.Items(ListView1.SelectedIndices(0)).SubItems(2).Text
            txtPrice.Text = ListView1.Items(ListView1.SelectedIndices(0)).SubItems(3).Text
            txtQty.Text = ListView1.Items(ListView1.SelectedIndices(0)).SubItems(4).Text
        End If
 
=========================

search

============= search
  Dim isSearch As Boolean = False
        If txtModel.Text <> "" And txtYear.Text <> "" Then
            strQ = "SELECT * FROM tbCar where Model like '%" & txtModel.Text & "%' and Year like '" & txtYear.Text & "' ORDER BY [Model]"
            isSearch = True

load data into listview

=========== load data into listview
'strQ = "SELECT * FROM tbCar ORDER BY [Model]"
'======>         load_data(strQ)
 Sub load_data(sqlQuery As String)
        Try
            If (con.State = ConnectionState.Open) Then
                con.Close()
            End If

connect or login

=============================  connect or login
 Private Sub ConnectToSQL()
        Dim Password As String
        Dim userName As String
        Try
            If (con.State = ConnectionState.Open) Then