how to create a login form in VB (vs 2008) with database

Question

Hi,
I am new with VB. I got now the Visual Studio 2008. I newer used it before.
I need the following:
    I need a login form, which is using an MS Access 2003 database, in which I stored usernames and passwords.
The DB name is users.mdb and is stored on the C drive. It contains just 1 table, the name of the table is UserList. In the table I have 3 colums, first is ID, second is Username, the third is Password. It contains just 4 datas, in the username the first entry is John, the second is Mary, in the password column the passwords are john and mary.

And now to the code.

I can add to the main form a "LoginForm" (from the VS2008 templates). The name is LoginForm1.vb
After this I am creating a connection to the database, as following:
       Solution Explorer --- click on Data Sources --- Add new Data Source. On the windo, which appeares, I choos Database, then click on next, next page --- New Connection --- DataSource is seted to Microsoft Access Database File (OLEDB) --- and Database filename is C:\users.mdb --- no authentication is needed --- Test Connection succeeded ---click on OK --- in the data source config wizzard click on next --- by the question "Save the connection string to the Application configuration file" I choose yes, and it will be saved as "usersConnectionString" --- I click on next --- by choosing my database objects I choose the "Username" and "Password" --- The DataSet name is "usersDataSet" --- and I click on Finish.
And here I am. I don't know, how to check if the value/text of the Username textbox is in the database, or not.

Here is the code of the login form, wich I got by adding the template LoginForm1.vb to the project:

Public Class LoginForm1

' TODO: Insert code to perform custom authentication using the provided username and password

' (See http://go.microsoft.com/fwlink/?LinkId=35339).

' The custom principal can then be attached to the current thread's principal as follows:

'     My.User.CurrentPrincipal = CustomPrincipal

' where CustomPrincipal is the IPrincipal implementation used to perform authentication.

' Subsequently, My.User will return identity information encapsulated in the CustomPrincipal object

' such as the username, display name, etc.

Private Sub OK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OK.Click

Me.Close()

End Sub

Private Sub Cancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Cancel.Click

Me.Close()

End Sub

Private Sub LoginForm1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

End Sub

End Class

Thank you for your help in advance.
IceFace

Answer 1

Hi IceFace,

Walkthrough: How to make a Login Verification routine?

e.g. Access Database file myDB.mdb contains a table Users.

Users table has the following two fields:
Field Name   Data Type
userid           Text
password      Text

Then you can add a template login form like this:
Project -> Add Windows Form -> Select template  "Login Form"

Login verification:
Prerequisites: usernametextbox TextBox, passwordtextbox TextBox, OK and Cancel buttons on Login Form.

Imports System.Data.OleDb

Public Class LoginForm1

' OK button

Private Sub OK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OK.Click

Dim con As New OleDbConnection("Provider=Microsoft.jet.oledb.4.0;data source=E:\VBproject\myDB.mdb")

Dim cmd As OleDbCommand = New OleDbCommand("SELECT * FROM Users WHERE userid = '" & usernametextbox.Text & "' AND password = '" & passwordtextbox.Text & "' ", con)

con.Open()

Dim sdr As OleDbDataReader = cmd.ExecuteReader()

' If the record can be queried, Pass verification and open another form.

If (sdr.Read() = True) Then

MessageBox.Show("The user is valid!")

Dim mainForm As New MainForm

mainForm.Show()

Me.Hide()

Else

MessageBox.Show("Invalid username or password!")

End If

End Sub

' Cancel button

Private Sub Cancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Cancel.Click

Me.Close()

End Sub

End Class

Trackback:
http://forums.msdn.microsoft.com/en-US/vbgeneral/thread/ab00db69-8f87-4456-b87e-d515c80e22db/
http://forums.msdn.microsoft.com/en-US/vblanguage/thread/de43bba7-5228-4d20-8b5c-9389029f4dae/


Best regards,
Martin Xie

Answer 2

Good tutorial thanks

Answer 3

Hi Martin,

Very clear and self explanatory!

Thx!

Answer 4

thanks 

i am student and now a days learning vb.net

your example for login form is great

Answer 5

Hi Martin,

 

Do you know of a way to use a datatable inside a dataset instead of using Access?

 

Thanks,

David

Answer 6

your post is a good tutorial but i have a problem when i try the LOGIN form i receieved an error

this my code

Imports System.Data.OleDb
Public Class LoginForm1

    ' TODO: Insert code to perform custom authentication using the provided username and password
    ' (See http://go.microsoft.com/fwlink/?LinkId=35339). 
    ' The custom principal can then be attached to the current thread's principal as follows:
    '     My.User.CurrentPrincipal = CustomPrincipal
    ' where CustomPrincipal is the IPrincipal implementation used to perform authentication.
    ' Subsequently, My.User will return identity information encapsulated in the CustomPrincipal object
    ' such as the username, display name, etc.

    Private Sub OK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OK.Click
        Dim con As New OleDbConnection("Provider=Microsoft.jet.oledb.4.0;data source=c:\db\user.mdb")
        Dim cmd As OleDbCommand = New OleDbCommand("SELECT * FROM Users WHERE userid = '" & UsernameTextBox.Text & "' AND password = '" & PasswordTextBox.Text & "' ", con)
        con.Open()
        Dim sdr As OleDbDataReader = cmd.ExecuteReader()
        ' If the record can be queried, Pass verification and open another form. 
        If (sdr.Read() = True) Then
            MessageBox.Show("The user is valid!")
            Dim mainForm As New Form3
            mainForm.Show()
            Me.Hide()
        Else
            MessageBox.Show("Invalid username or password!")
        End If
    End Sub

    Private Sub Cancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Cancel.Click
        Me.Close()
    End Sub

    Private Sub LoginForm1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load


    End Sub
End Class

 

I have an error in these Line

Dim sdr As OleDbDataReader = cmd.ExecuteReader()

and the error statement is below

Oledbexception was unhandled

The Microsoft Jet database engine cannot find the input table or query 'Users'.  Make sure it exists and that its name is spelled correctly.

 

please help me

Answer 7

Eish! me too

i think the problem might be the path but i dont knw where should i locate my database

Your help will be appriciated

Ooh-Bee

Answer 8

Unless you are the OP I would recommend posting a new question to the forum. It isn't likely that you will receive help in a thread that's several years old.

---

Paul ~~~~ Microsoft MVP (Visual Basic)

Answer 9

Hi when using access as a database you need to know that Password is a protected word putting [] around password will help and just for good measure I put [] around all Example:  "SELECT * FROM [UserDetails] WHERE [Username]= ('" + LoginUsername.Text + "') AND [Password] = ('" + LoginPassword.Text + "')"

Answer 10

it shows "No value given for one or more required parameters."