Wrong username or Wrong password

[jamesbon007]

Hi everyone,

I've managed to write some code which allows me to login into my application. However i would like to notify the user if he or she enters the wrong username or the wrong password? Am not sure how to go about this.

This is what i got so far

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

        Dim conn As New OleDb.OleDbConnection("Provider=sqloledb;Data Source=GSTT-CVC-R1;Initial Catalog=TestDp;User Id=Test;Password=testpass;")
        Dim sql As String
        FileSystem.FileOpen(2, "C:\temp\test.txt", OpenMode.Append, OpenAccess.ReadWrite, OpenShare.Shared)


        Dim userlogin, userpassword As String

        userlogin = txtLogin.Text
        userpassword = txtPassword.Text

        sql = "SELECT * from tbl_users where LoginName = '" & userlogin & "' AND LoginPassword = '" & userpassword & "'"


        Dim mycmdReader As New OleDb.OleDbCommand(sql, conn)
        Dim LoginReader As System.Data.OleDb.OleDbDataReader

        Try
            conn.Open()
            LoginReader = mycmdReader.ExecuteReader
            FileSystem.PrintLine(2, "Open connection" & "***" & Now())

        Catch ex As Exception
            MsgBox(Err.Description)
            FileSystem.PrintLine(2, "Error: " & Err.Description & "***" & Now())
            Exit Sub

        End Try

        If LoginReader.HasRows Then
            LoginReader.Read()
            FileSystem.PrintLine(2, "LOGGED IN: " & userlogin & "***" & Now())


        Else
            FileSystem.PrintLine(2, "LOGIN FAILED" & "***" & Now())
        End If

        FileSystem.FileClose(2)
    End Sub

 

[jshultz]

To get you started in the right direction i'll just tell you what I do.

I pull everything, similar to what you are doing, from my users table but my where clause only contains the username, not the password.
Then, if it returns 0 rows you know the username is incorrect. If it returns a row, simply compare the entered password against what you pulled from the table.