[20908]

كود :

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

    Dim UserLogin As Boolean = False

    Using da As New OleDb.OleDbDataAdapter("SELECT COUNT(*) FROM [Table1] WHERE ([UserName]=@un) AND ([Password]=@pw)", con)
        da.SelectCommand.Parameters.AddWithValue("@un", txtUserName.Text)
        da.SelectCommand.Parameters.AddWithValue("@pw", txtPassword.Text)
        Dim dt As New DataTable
        If da.Fill(dt) > 0 Then
            UserLogin = True
        Else
            MsgBox("Username or Password not valid")
        End If
    End Using

    If UserLogin Then

        Using da As New OleDb.OleDbDataAdapter("SELECT * FROM [UserVisit] WHERE ([UserName]=@un)", con)
            da.SelectCommand.Parameters.AddWithValue("@un", txtUserName.Text)
            Dim dt As New DataTable
            If da.Fill(dt) > 0 Then
                Label1.Text = dt.Rows.Cast(Of DataRow).Last.Item("Visit")
            Else
                Label1.Text = "First visit."
            End If

            DataGridView1.DataSource = dt

        End Using

        Using cmd As New OleDb.OleDbCommand("INSERT INTO [UserVisit] ([UserName],[Visit]) VALUES(@un,Now)", con)
            cmd.Parameters.AddWithValue("@un", txtUserName.Text)
            If con.State <> ConnectionState.Open Then con.Open()
            cmd.ExecuteNonQuery()
            con.Close()

        End Using

    End If
End Sub