MENU UTAMA DAN LOGIN

Di MENU UTAMA biasanya ada :
1. admin hak aksesnya sebagai Supervisor
2. user hak aksesnya ada pembatasnya

Langkah-langkahnya :
1. buat tabel login

Kita buat Data Percobaan :

Kita buat Form Login

Beri nama : textbox nya : txtuser, txtpass, cbakses

Karena ini menggunakan DataBase MYSQL
Kita buat Modul dan Koneksi ke DataBase MySQL
Syarat : Anda sudah Install Xampp dan Connection Mysql NET versi 6.5.4 dan VB.net(VB-2010)
kita buat Koneksi ke MYSQL biasa pojok kanan atas Klik Kanan > Add Reference sampai
pilih Browse cari di c:\Program files\Mysql\Mysql Connector Net 6.5.4
lalu blok semua - OK

Kemudian buat Modulnya buat Coding konek nya

lalu buat Codingnya

Imports MySql.Data.MySqlClient
Imports System.Data
Module modulku
    Public cmd As New MySqlCommand
    Public dadapter As New MySqlDataAdapter
    Public datardr As MySqlDataReader
    Public strSql As String
    Dim serv As String = "Server=localhost;"
    Dim dbase As String = "Database=toko;"
    Dim uid As String = "uid=root;"
    Dim pwd As String = "pwd=;"
    Dim ConString = serv & dbase & uid & pwd
    Public db As New MySqlConnection(ConString)
    Public Sub konek()
        Try
            tutupDB()
            db.Open()
            MsgBox("Koneksi DataBase berhasil dilakukan")
        Catch ex As MySqlException
            MsgBox(ex.Message)
            MsgBox("Koneksi tidak berhasil dilakukan")
        End Try
    End Sub
    Public Sub tutupDB()
        If db.State = ConnectionState.Open Then
            db.Close()
        End If
    End Sub

End Module

Kemudian buat Form2 sebagai Form Utama ( Menu Utama )

Kemudian Coding untuk Form1 ( Login )

Imports MySql.Data.MySqlClient
Public Class Form1
    Private Sub TampilData()
        Dim da As New MySqlDataAdapter("select USERNAME,PASSWORD,HAKAKSES from tbl_login", db)
        'Dim da As New MySqlDataAdapter("select * from tbl_login", db)

        Dim dt As New DataTable
        da.Fill(dt)
        dgv.DataSource = dt


        'Dim query As String = "SELECT * FROM CUSTOMER"
        ' Dim da As New MySqlDataAdapter(query, db)
        ' Dim ds As New DataSet()

        'If da.Fill(ds) Then
        'dgv.DataSource = ds.Tables(0)
        'End If

    End Sub
    Private Sub CekData()
        konek()
        Try
            strSql = "SELECT * FROM tbl_login where trim(username) ='" & Trim(txtuser.Text) & "' AND Password='" & Trim(txtpass.Text) & "'"
            cmd.CommandText = strSql
            cmd.Connection = db
            dadapter.SelectCommand = cmd

            datardr = cmd.ExecuteReader
            If datardr.HasRows Then
                datardr.Read()
                ' MessageBox.Show("Kombinasi Username ,Password dan Hak Akses Benar", "Konfirmasi", MessageBoxButtons.OK, MessageBoxIcon.Error)
                cbakses.Text = datardr("hakakses")

                If cbakses.Text = "admin" Then
                    'Jika Hak akses adalah admin
                    Form2.Show()                                                'Tampilkan Form2
                    Me.Hide()
                Else                                                            'Jika Hak Akses bukan admin (user)
                    Form2.DataMahasiswaToolStripMenuItem.Enabled = False        'disable submenu data mahasiswa di form 2
                    Form2.DataDosenToolStripMenuItem.Enabled = False            'disable submenu data dosen di form 2
                    Form2.Show()                                                'Tampilkan Form2
                    Me.Hide()
                End If

            Else
                'Munculkan messagebox pesan salah
                MessageBox.Show("Kombinasi Username ,Password dan Hak Akses Salah", "Konfirmasi", MessageBoxButtons.OK, MessageBoxIcon.Error)
                txtuser.Focus()
            End If

            ' datardr.Close()
            ' cmd.Dispose()
            ' db.Close()
        Catch ex As Exception

        End Try

    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        konek()
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        TampilData()
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        CekData()
    End Sub
End Class

Kemudian Jalankan (Debug)
Kita coba pakai nama abu sebagai user