Password validation

Hi all,

i am trying to write a password validation function, here is what i have so far:

Code:

---

 

    Private Sub btnSubmit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSubmit.Click

        'validate user login

        'check both fields contain some info
        If txtUserName.Text = "" Or txtPassword.Text = "" Then
            MsgBox("You must enter a valid username and password to continue.  Blank fields are not accepted.")
        Else
            'grab the user input
            uname = txtUserName.Text
            pwd = txtPassword.Text
            'create filter/dataiew
            Dim dv As New DataView(DsLogin1.Tables("tblpwd"))
            dv.RowFilter = "Username = 'uname' AND Password = 'pwd'"
            If dv.Count = 1 Then
                'open main form
                Dim frm1 As New frmMain
                frm1.Show()
            Else
                MsgBox("You have entered an invalid password, please try again.")
            End If
        End If

    End Sub

---

It runs but doesn't find the username or password.

any help appreciated.

At first glance, my guess is that you are referencing a table that doesn't exist in your dataset, "tblpwd" but I don't know how this dataset is getting populated or how you know that the name of the table is "tblpwd".

If you are accessing data and filling a dataset in the usual way then your table name is probably not "tblpwd" as you expect, but is actually "Table".

The reason is when you fill a dataset using the dataadapter.fill method, event though your select statement indicates what table you are selecting data from, your dataset names it "Table", "Table2" . . . etc.

Try altering this line:

VB Code:

Dim dv As New DataView(DsLogin1.Tables("tblpwd"))

to this:

VB Code:

Dim dv As New DataView(DsLogin1.Tables("Table"))

Hi and thanks for yout reply,

I am filling the dataset at the time the form is loaded:

Code:

---


conn1.open()
oleda.Fill(dslogin)

---

I have tried replacing the tblpwd with Table in it still returns exactly the same

Quote:

---

Originally posted by dagoose
Hi and thanks for yout reply,

I am filling the dataset at the time the form is loaded:

Code:

---


conn1.open()
oleda.Fill(dslogin)

---

I have tried replacing the tblpwd with Table in it still returns exactly the same

---

Looks like you have not populated oleda

Not necessarily taxes, if he is referencing the wrong table, or is not providing valid values for his rowfilter property then he could be receiving an empty value when he queries his dataview.

How many tables are in your dataset?
Also, are you absolutely certain that you are passing a valid username and password in your rowfilter. I have code here that works just fine and does return the one row that I expect it to.

VB Code:

Private Sub btnGetCustInfo_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGetCustInfo.Click
        Dim dt As New DataTable("Customers")
        dt.Columns.Add("location", System.Type.GetType("System.String"))
        dt.Columns.Add("country", System.Type.GetType("System.String"))
        dt.Columns.Add("lasttime", System.Type.GetType("System.String"))
        Dim oReader As New StreamReader("C:\bin\LastImport.CSV")
        Dim oCust As String
        Dim Delim As String = ","
        Dim oData() As String
        Dim Index As Int32
        Dim drItem As DataRow
        oCust = oReader.ReadLine
        Do
            oData = oCust.Split(Delim.ToCharArray)
            drItem = dt.NewRow
            For Index = oData.GetLowerBound(0) To oData.GetUpperBound(0)
                drItem(Index) = oData(Index).ToString
            Next
            dt.Rows.Add(drItem)
            drItem = Nothing
            oCust = oReader.ReadLine
        Loop Until oCust Is Nothing
        Dim dv As New DataView(dt)
        dv.RowFilter = "location = '510'"
        Me.DataGrid1.DataSource = dv
    End Sub

Quote:

---

Originally posted by CyberHawke
Not necessarily taxes, if he is referencing the wrong table, or is not providing valid values for his rowfilter property then he could be receiving an empty value when he queries his dataview.

---

Doesn't he have to populate the dataadapter AFTER he has opened the connection?

No, the code is correct asuming that the dataadapter is a module level object that already has a command associated with it.

What he does not have to do is open his connection. As long as it is associated with the dataadapter, it will open long enough to retrieve his data and the automatically close again.

Quote:

---

Originally posted by CyberHawke
No, the code is correct asuming that the dataadapter is a module level object that already has a command associated with it.

What he does not have to do is open his connection. As long as it is associated with the dataadapter, it will open long enough to retrieve his data and the automatically close again.

---

But if what he posted is the first, and only, time he opened the connection...........?

Then it will eventually close again after a period of inactivity. The point is that by explicitly opening a connection, you are using up resources on the server in a wasteful way. It is better to have dynamic connections that are opened and closed as DataAdapters consume them.

example :
http://www.vbforums.com/showthread.p...hreadid=250863

Quote:

---

Originally posted by CyberHawke
Then it will eventually close again after a period of inactivity. The point is that by explicitly opening a connection, you are using up resources on the server in a wasteful way. It is better to have dynamic connections that are opened and closed as DataAdapters consume them.

---

Sorry but that is nothing to do with what we are discussing. My comment refers to the coding posted as

conn1.open()
oleda.Fill(dslogin)

If this is the only time conn1 is opened, should oleda be then populated before dslogin can be filled?

I apologize if I am way off base, I don't really know .NET yet,
but it looks like you are not passing in the variable values of Username and Password:

Should this:
dv.RowFilter = "Username = 'uname' AND Password = 'pwd'"

be structured like this?
dv.RowFilter = "Username = '" & uname & "' AND Password = '" & pwd & '"

Quote:

---

Originally posted by bubba
I apologize if I am way off base, I don't really know .NET yet,
but it looks like you are not passing in the variable values of Username and Password:

Should this:
dv.RowFilter = "Username = 'uname' AND Password = 'pwd'"

be structured like this?
dv.RowFilter = "Username = '" & uname & "' AND Password = '" & pwd & '"

---

For crimminy sakes! How long was this thread going to go before some one go it right! Took me all of 5 seconds to spot this.

Bravo bubba ! :thumb:

TG

I guess it takes a simple mind to find the simple solution?

That made my day HA HA.

Yeah I didn't notice that either, I was thinking that he did not fill up his dataset correctly.

By golly...

Quote:

---

Originally posted by bubba
I guess it takes a simple mind to find the simple solution?

---

Ah, don't kid yourself. It's those little things in life. Sometimes when some one has been staring at the same code for too long they can't see what's wrong with it, and it usualy takes a pair of fresh eyes to lookat it.

TG

Use this to fill a combobox with all your usernames:


In frmMain.Load Event

Code:

---

  cmbUsername.DataSource = DsEmployeeInformation.Employee_Information
cmbUsername.DisplayMember = "Name"

---

Then use this to determine a valide password for the selected username:


In btnLogin.Click Event

Code:

---

With dsEmployeeInformation.Employee_Information
    If Convert.ToString(.Rows(cmbUsername.SelectedIndex)("Password")) = txtPassword.Text Then
        Dim frmNew As New frmNew
        frmNew.showdialog()
      Else
        MessageBox.Show("Invalid Password!")
        txtPassword.Text = ""
    End If
End With

---

Very simple and works great!:)