How to create a txt file that records login details? VB.NET - vb.net

Question

I wanna create a txt file that stores the Username, Password, Date & Time, and User Type when "Log In" button is pressed. But all I know is how to create a txt file. Can anyone help me? Here's my code for my Log In button:
Private Sub btnLogin_Click(sender As Object, e As EventArgs) Handles btnLogin.Click
Dim username As String = ""
Dim password As String = ""
Dim cn As New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;" & "Data Source=D:\Library Management System\LMS_Database.accdb")
Dim cmd As OleDbCommand = New OleDbCommand("SELECT ID_Number FROM Users WHERE ID_Number = '" & txtUsername.Text & "' AND ID_Number = '" & txtPassword.Text & "'", cn)
cn.Open()
Dim dr As OleDbDataReader = cmd.ExecuteReader()
If (dr.Read() = True And cboUserType.Text = "Student") Then
MsgBox("Welcome!", MsgBoxStyle.OkOnly, "Successfully logged in.")
frmViewBooks.Show()
txtUsername.Clear()
txtPassword.Clear()
cboUserType.SelectedIndex = -1
Me.Hide()
Else
If (txtUsername.Text = "admin" And txtPassword.Text = "ckclibraryadmin" And cboUserType.Text = "Administrator") Then
MsgBox("Welcome, admin!", MsgBoxStyle.OkOnly, "Successfully logged in.")
frmAdminWindow.Show()
txtUsername.Clear()
txtPassword.Clear()
cboUserType.SelectedIndex = -1
Me.Hide()
Else
MsgBox("Your username or password is invalid. Please try again.", MsgBoxStyle.OkOnly, "Login failed.")
txtUsername.Clear()
txtPassword.Clear()
cboUserType.SelectedIndex = -1
End If
End If
End Sub
I'd be getting the Date and Time value from my timer.
Private Sub frmLogIn_Load(sender As Object, e As EventArgs) Handles MyBase.Load
tmrLogIn.Start()
End Sub
Private Sub tmrLogIn_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tmrLogIn.Tick
lblTime.Text = DateTime.Now.ToString()
End Sub
Thank you!

Answer 1

There are a few things that I'd like to point out to maybe help you later on down the road. Data object generally implement iDisposable, it is a good idea to either wrap them in Using statements or dispose of them manually. Also, it is generally a good idea to wrap any database code into a Try/Catch exception handler because something can go wrong at any point you're trying to access outside data. Also, it is always a good idea to parameterize your query. Finally, you are only wanting to validate that a row is returned from your SQL statement, so your SQL statement should instead return the number of rows returned and then you can use the ExecuteScalar to get that one value returned.
With all of that out of the way, all you would need to do is append a line to a text file using the IO.File.AppendAllLines method using the data you already have if the login was validated.
Here is an example of implementing everything I suggested:
'Declare the object to return
Dim count As Integer = -1
'Declare the connection object
Dim con As OleDbConnection
'Wrap code in Try/Catch
Try
'Set the connection object to a new instance
con = New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;" & "Data Source=D:\Library Management System\LMS_Database.accdb")
'Create a new instance of the command object
'TODO: If [Username] and [Password] are not valid columns, then change them
Using cmd As OleDbCommand = New OleDbCommand("SELECT Count([ID_Number]) FROM [Users] WHERE [Username] = #username AND [Password] = #password", con)
'Parameterize the query
With cmd.Parameters
.AddWithValue("#username", txtUsername.Text)
.AddWithValue("#password", txtPassword.Text)
End With
'Open the connection
con.Open()
'Use ExecuteScalar to return a single value
count = Convert.ToInt32(cmd.ExecuteScalar())
'Close the connection
con.Close()
End Using
If count > 0 Then
'Append the data to the text file
'TODO: Change myfilehere.txt to the desired file name and location
IO.File.AppendAllLines("myfilehere.txt", String.Join(",", {txtUsername.Text, txtPassword.Text, DateTime.Now, cboUserType.Text}))
'Check if it is a student or admin
If cboUserType.Text = "Student" Then
'Inform the user of the successfull login
MessageBox.Show("Welcome!", "Login Successfull", MessageBoxButtons.OK)
frmViewBooks.Show()
ElseIf cboUserType.Text = "Administrator" Then
'Inform the admin of the successfull login
MessageBox.Show("Welcome, admin!", "Login Successfull", MessageBoxButtons.OK)
frmAdminWindow.Show()
End If
'Reset and hide the form
txtUsername.Clear()
txtPassword.Clear()
cboUserType.SelectedIndex = -1
Me.Hi
Else
'Inform the user of the invalid login
MessageBox.Show("Invalid username and/or password. Please try again.", "Invalid Login", MessageBoxButtons.OK)
End If
Catch ex As Exception
'Display the error
Console.WriteLine(ex.Message)
Finally
'Check if the connection object was initialized
If con IsNot Nothing Then
If con.State = ConnectionState.Open Then
'Close the connection if it was left open(exception thrown)
con.Close()
End If
'Dispose of the connection object
con.Dispose()
End If
End Try

Answer 2

Your goal can be achieved in many ways.For example,you can create an access/sql/mysql database to store the required information.But if u want to use a textfile instead,you can store Username,password and other details on seperate lines.Then you can read each line from the text file and use it the way you want.So,which one u prefer? a database or text file? leave a comment and i'lll add the codes/instructions depending on your choice