Listing program Vb.Net 2012

LOGIN

    Private Sub btn_masuk_Click(sender As Object, e As EventArgs) Handles btn_masuk.Click

        Try
            connect.Open()
            Console.WriteLine("koneksi sukses")

            command.Connection = connect
            command.CommandType = CommandType.Text
            '            command.CommandText = "SELECT * FROM login WHERE nama = '" & tb_user.Text & "' and password='" & tb_pass.Text & "'"
            command.CommandText = "select * from login where login.nama = '" & tb_user.Text & "' and login.password = '" & tb_pass.Text & "'"
            reader = command.ExecuteReader
            reader.Read()
            If reader.HasRows = True Then
                username = reader("nama")
                pass = reader("password")
                MessageBox.Show("Data ada" & username & " " & pass)
                MenuUtama.Show()
            Else
                MessageBox.Show("Tidak ada data")
            End If

            connect.Close()

        Catch ex As Exception
            Console.WriteLine("gagal: " & ex.ToString)
        End Try
    End Sub

FORM

' Untuk memanggil fungsi penghubung ke database
Imports System.Data
Imports System.Data.SqlClient

Public Class kereta
    'Untuk menghubungkan ke database

    Dim connect As New SqlConnection("Server=ABDU-PC\SQLEXPRESS;Database=reservasi_kereta;Trusted_Connection=True")

    Dim command As New SqlCommand

    Dim reader As SqlDataReader

    Dim data As DataTable
    Dim adapter As SqlDataAdapter

    Private Sub refresh_tampilan()

        ' UNTUK MENAMPILKAN DATA PADA DATA GRID
        Try
            connect.Open()
            Console.WriteLine("koneksi sukses")


            adapter = New SqlDataAdapter("SELECT * FROM kereta", connect)
            data = New DataTable()
            adapter.Fill(data)
            DataGridView1.DataSource = data
            connect.Close()

        Catch ex As Exception
            Console.WriteLine("gagal: " & ex.ToString)
        End Try
    End Sub

    Private Sub kereta_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ' Untuk Menambahkan item pada ComboBOX

        txt_id_class.Items.Add("Eksekutif")
        txt_id_class.Items.Add("Ekonomoi")
        txt_id_class.Items.Add("Bisnis")

        btn_hapus.Enabled = False
        btn_simpan.Enabled = False
        btn_ubah.Enabled = False

        refresh_tampilan() ' merefresh data
    End Sub

    ' Menampilkan data pada text
    Private Sub DataGridView1_CellContentClick(sender As Object, e As DataGridViewCellEventArgs) Handles DataGridView1.CellContentClick
        Dim i As Integer
        i = DataGridView1.CurrentRow.Index
        With DataGridView1.Rows.Item(i)
            txt_nokereta.Text = .Cells("Nomor_Kereta").Value
            txt_namakereta.Text = .Cells("Nama_Kereta").Value
            txt_id_class.Text = .Cells("Id_Class").Value
            txt_price.Text = .Cells("Price").Value

            'Untuk memunculkan atau menyembunyikan buton pada database (TRUE (menyala) FALSE (tidur) )

            btn_tambah.Enabled = True
            btn_simpan.Enabled = False
            btn_ubah.Enabled = True
            btn_hapus.Enabled = True




        End With
    End Sub

    Private Sub btn_tambah_Click(sender As Object, e As EventArgs) Handles btn_tambah.Click
        ' untuk memberikan ruang kosong pada database

        txt_nokereta.Text = " "
        txt_namakereta.Text = " "
        txt_id_class.Text = " "
        txt_price.Text = " "

        btn_ubah.Enabled = False
        btn_hapus.Enabled = False
        btn_simpan.Enabled = True

    End Sub

    Private Sub btn_ubah_Click(sender As Object, e As EventArgs) Handles btn_ubah.Click
        Try
            connect.Open() ' membuka koneksi
            Console.WriteLine("Koneksi sukses") ' memberikan pesan jika koneksi terhubung
            command.Connection = connect ' identifikasi bahwa command connection adalah variabel connect
            command.CommandText = "UPDATE kereta set Nomor_Kereta = '" & txt_nokereta.Text & "', Nama_Kereta = '" & txt_namakereta.Text & "', Id_Class = '" & txt_id_class.Text & "', Price = '" & txt_price.Text & "' where Nomor_Kereta = '" & txt_nokereta.Text & "'" ' Untuk membuat Query
            command.ExecuteNonQuery() ' Untuk menjalankan perintah Sql
            MessageBox.Show("Data berhasil di ubah") ' Untuk memberikan Pesan
            connect.Close() ' Menutup Koneksi Sql

            refresh_tampilan() ' Merefresh data setelah di ubah

        Catch ex As Exception
            Console.WriteLine("Gagal: " & ex.ToString)


        End Try
    End Sub

    Private Sub btn_hapus_Click(sender As Object, e As EventArgs) Handles btn_hapus.Click
        'FUNGSI UNTUK MENGHAPUS DATA

        Try
            connect.Open()
            Console.WriteLine("Koneksi Sukses")
            command.Connection = connect
            command.CommandText = "Delete from kereta where Nomor_Kereta = '" & txt_nokereta.Text & "'"
            command.ExecuteNonQuery()
            MessageBox.Show("Data berhasil di hapus")
            connect.Close()

            refresh_tampilan() ' merefresh data yang telah terhapus

        Catch ex As Exception
            Console.WriteLine("Gagal: " & ex.ToString)
        End Try



    End Sub

    Private Sub btn_simpan_Click(sender As Object, e As EventArgs) Handles btn_simpan.Click
        'Untuk menambahkan data pada database

        Try
            connect.Open()
            Console.WriteLine("koneksi sukses")
            command.Connection = connect
            command.CommandText = "INSERT INTO kereta VALUES('" & txt_nokereta.Text & "','" & txt_namakereta.Text & "','" & txt_id_class.Text & "','" & txt_price.Text & "')"
            command.ExecuteNonQuery()
            MessageBox.Show("Data berhasil ditambah")
            connect.Close()

            refresh_tampilan()

        Catch ex As Exception
            Console.WriteLine("gagal: " & ex.ToString)
        End Try

    End Sub

    Private Sub btn_keluar_Click(sender As Object, e As EventArgs) Handles btn_keluar.Click
        Me.Close()

    End Sub
End Class