Wednesday, March 22, 2023

VB.NET WINDOWSFORM WITH SQL DATABASE (1)


ON THIS POST,I WILL SHARE THE CODES FOR CONNECTING SQL DATABASE WITH VB.NET WINDOWS FORM







CODES:





CODES:







Imports System.Data.SqlClient

Public Class Form1



    Dim con As New SqlConnection

    Dim cmd As New SqlCommand

    Private i As Integer

    Public Const WM_NCLBUTTONDOWN As Integer = &HA1



    Public Const HT_CAPTION As Integer = &H2





    Private Sub Label1_Click(sender As Object, e As EventArgs) Handles Label1.Click

        Application.Exit()

    End Sub



    Private Sub Panel1_MouseDown(sender As Object, e As MouseEventArgs) Handles Panel1.MouseDown

        If e.Button = Windows.Forms.MouseButtons.Left Then



            rcmove.ReleaseCapture()



            rcmove.SendMessage(Handle, WM_NCLBUTTONDOWN, HT_CAPTION, 0)



        End If

    End Sub



    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

        On Error Resume Next

        con.ConnectionString = "Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\wolve\OneDrive\Desktop\2019\RC\RC\RCConnection.mdf;Integrated Security=True"

        If con.State = ConnectionState.Open Then

            con.Close()

        End If

        con.Open()

        '========================================================

        Dim constr As String = "Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\wolve\OneDrive\Desktop\2019\RC\RC\RCConnection.mdf;Integrated Security=True"

        Using con As SqlConnection = New SqlConnection(constr)

            Using sda As SqlDataAdapter = New SqlDataAdapter("SELECT ID, username FROM userD", con)

                'Fill the DataTable with records from Table.

                Dim dt As DataTable = New DataTable()

                sda.Fill(dt)

                Dim row As DataRow = dt.NewRow()

                row(0) = 0

                ' row(1) = "Select Here"

                dt.Rows.InsertAt(row, 0)

                comSearch.DataSource = dt

                comSearch.DisplayMember = "username"

                comSearch.ValueMember = "ID"

            End Using

        End Using



    End Sub

    Private Function UserExists(fname As String, lname As String) As Boolean

        Dim SQLConnect As String = "Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\wolve\OneDrive\Desktop\2019\RC\RC\RCConnection.mdf;Integrated Security=True"

        Dim con As New SqlConnection(SQLConnect)

        con.Open()

        Dim cmd As SqlCommand = con.CreateCommand

        cmd.CommandText = "SELECT COUNT(*) FROM userD" &

                          " WHERE username  = '" & txtUser.Text & "'"



        UserExists = cmd.ExecuteScalar > 0

        If UserExists = False Then

            cmd = con.CreateCommand()

            cmd.CommandType = CommandType.Text

            cmd.CommandText = "insert into userD values('" + txtUser.Text + "','" + txtPass.Text + "')"

            cmd.ExecuteNonQuery()

            txtUser.Text = ""

            txtPass.Text = ""

            MessageBox.Show("User Inserted Successfully")

            '===============



            '========================================================

            Dim constr As String = "Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\wolve\OneDrive\Desktop\2019\RC\RC\RCConnection.mdf;Integrated Security=True"

            Using cons As SqlConnection = New SqlConnection(constr)

                Using sda As SqlDataAdapter = New SqlDataAdapter("SELECT ID, username FROM userD", con)

                    Dim dt As DataTable = New DataTable()

                    sda.Fill(dt)

                    Dim row As DataRow = dt.NewRow()

                    ' row(0) = 0

                    ' row(1) = "Select Here"

                    dt.Rows.InsertAt(row, 0)

                    comSearch.DataSource = dt

                    comSearch.DisplayMember = "username"

                    comSearch.ValueMember = "ID"

                End Using

            End Using

            '================

        Else

            MessageBox.Show("User EXIST!")

        End If

        con.Close()



    End Function



    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

        UserExists(txtUser.Text, "")

    End Sub





    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click

        On Error Resume Next



        cmd = con.CreateCommand()

        cmd.CommandType = CommandType.Text

        cmd.CommandText = "select * from userD where username='" + comSearch.Text + "'"

        cmd.ExecuteNonQuery()

        Dim dt As New DataTable()



        Dim da As New SqlDataAdapter(cmd)

        da.Fill(dt)

        ' DataGridView1.DataSource = dt

        '========================================

        Dim dr As SqlClient.SqlDataReader

        dr = cmd.ExecuteReader(CommandBehavior.CloseConnection)

        While dr.Read

            txtUser.Text = dr.GetString(1).ToString()

            txtPass.Text = dr.GetString(2).ToString()

        End While

    End Sub



    Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click

        If con.State = ConnectionState.Open Then

            con.Close()

        End If

        con.Open()

        cmd = con.CreateCommand()

        cmd.CommandType = CommandType.Text

        cmd.CommandText = "delete from userD where username='" + comSearch.Text + "'"

        cmd.ExecuteNonQuery()

        '======================

        Dim constr As String = "Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\wolve\OneDrive\Desktop\2019\RC\RC\RCConnection.mdf;Integrated Security=True"

        Using cons As SqlConnection = New SqlConnection(constr)

            Using sda As SqlDataAdapter = New SqlDataAdapter("SELECT ID, username FROM userD", con)

                Dim dt As DataTable = New DataTable()

                sda.Fill(dt)

                Dim row As DataRow = dt.NewRow()

                dt.Rows.InsertAt(row, 0)

                comSearch.DataSource = dt

                comSearch.DisplayMember = "username"

                comSearch.ValueMember = "ID"

            End Using



        End Using

        '=========================

        '  disp_data()

    End Sub

End Class











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