Information is very important to
us as human being this information is very useful in making decisions in our
day to day lives. Now every individuals
is equip with different devices and gadgets which enables them to communicate,
read news from the Internet, do some buying and selling in the Internet. But the biggest question is how secure our
information whether it is stored in the Internet or on our own computer. Generally speaking one of the most important
issues is all about computer security that most people is not bothered with.
Why because some people think if you use difficult username and password in
your computer or your account the in web you are already secure and having a
peace of mind because you know no body has the access to your account but only
you alone.
Again this presumption is not
correct most of the time, hackers and other people that has a high level of technical
skills and knowledge in computers were able to gather information about any
person and use those information for their own benefit. We have heard many
times hackers able to get and stoles thousands or even millions of credit card
numbers from banks and financial institution worldwide and sold this credit
card numbers including the information of the person online with the right
price you can get one and use it in your shopping or business transactions. Why this things
happened because there are security issues and problems were discovered in
banks information system that hackers will able to exploit. Sometimes this
loopholes in the system was also discovered by bank employees or IT personnel
in the bank that they have a direct access in the system. As I said in any bank or even financial
institution they should practice security audit from time to time to know what
are the problems or bugs in their system to avoid to be the next victim of
hackers or intruders.
In this article I will discuss
and show you how to create a database drive login system using Microsoft Visual
Basic .NET as my programming language and Microsoft Access 2007 as my database.
I called this program login system using
Microsoft Visual Basic 2010 and Microsoft Access 2007. To be honest this is my first database
application that I wrote using Visual Basic .NET because most of the time I
used Microsoft Visual Basic 6 as my tool in creating customized database
application for my clients here in the Philippines. But I think learning the new version of Visual
Basic is very important skills in today's information technology driven society
and also to upgrade my skills in programming tool. By
contrary database programming in Visual Basic .NET is much easier compared to
Visual Basic 6 why because all the necessary commands for database access is
already built in and the user interface is excellent in my own opinion.
I started designing first my user
interface in a form I named the form login system in its caption. The
background of the form I choose light green it is my own preference you can select the colour that you want in
your program it doesn't matter it is more of the personal choose. Next in line
I draw two text box the txtusername and txtpassword that will accept the user
name and password of the user. I also write the labels to give the use the idea
what to do the first label asking the user to enter the user name, the second
label is asking the user to enter the password. There are also two command buttons the OK and
CLOSE. The OK command button if the user already type the username and
password and then click the OK button it
will check if the username and password exist in our table named login in our
Microsoft Access database named user. If the user choose the close command
button the program will close and it will return to our windows operating
system. In my case the computer that I am using in writing and developing this
program I am using Microsoft Window 8.
About the code I make sure the
code is short and easy to understand by my fellow programmer. I am using
connection string to allow me to connect Microsoft access 2007 database to my
visual basic code as usually we must use SQL statement to do some queries in
our table. In our SQL statement we issue a command SELECT username,password
FROM login where username=? and password=? this statement tell SQL that we
select fields username and password to check if the username and password
provided by our user in our form is correct or not. I also use a function in Visual Basic .NET to
convert username and password into lowercase the command is ToLower(). Every
time a user type username and password even the user type in capital or
combination of uppercase and lowercase our program will convert all the user
name and password into lower case. If the user name and password is correct our
program will congratulate the user is not it will give a chance to the user to
key in once again the correct user name and password in our program.
Sample Output of Our Program
Program Listing
Imports System.Data.OleDb
Public Class frmlogin
Private Sub
Btn_login_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
btn_login.Click
Dim con As New OleDb.OleDbConnection
con.ConnectionString = "PROVIDER=Microsoft.JET.OLEDB.4.0;Data
Source = ..\user.mdb"
Dim cmd As OleDbCommand = New
OleDbCommand("SELECT
username,password FROM login where username=? and password=?", con)
cmd.Parameters.AddWithValue("username",
Me.txt_username.Text)
cmd.Parameters.AddWithValue("password",
Me.txt_password.Text)
Try
con.Open()
Dim read As OleDbDataReader = cmd.ExecuteReader()
If read.HasRows Then
read.Read()
If Me.txt_username.Text.ToLower()
= read.Item("username").ToString And Me.txt_password.Text.ToLower
= read.Item("password").ToString Then
MsgBox("You have login in the system
successfully.", MsgBoxStyle.Information,
"For your information")
Me.Hide()
ElseIf String.IsNullOrEmpty(Me.txt_username.Text) Or
String.IsNullOrEmpty(Me.txt_username.Text)
Then
MsgBox("Please make sure the username and
password is not empty.", MsgBoxStyle.Exclamation,
"Warning")
End If
Else
MsgBox("Username and Password is
incorrect. " & vbCrLf &
"
Access Denied !!! Please Try Again.", MsgBoxStyle.Exclamation,
"Warning")
Me.txt_username.Text = ""
Me.txt_password.Text = ""
Me.txt_username.Focus()
End If
read.Close()
Catch ex As Exception
MessageBox.Show(ex.Message)
Finally
con.Close()
End Try
End Sub
Private Sub
btn_close_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
btn_close.Click
End
End Sub
End Class
