Many interactive websites nowadays require a user to
log in into the website's system to provide a customized
experience for the user. Once the user has logged in,
the website will be able to provide a presentation that
is personalized to the user's preferences.
A basic login system typically contains 3 components
which can be created using PHP and MySQL :
Component 1: Allows registration of preferred login
Id and password.
This is created in simple HTML form that contains
3 fields and 2 buttons:
1. A preferred login id field
2. A preferred password field
3. A valid email address field
4. A Submit button
5. A Reset button
Lets say the form is coded into a file named register.html.
The following HTML code extract is a typical example.
When the user has filled in all the fields and clicks
on the submit button, the register.php page is called
for.
[form name="register" method="post"
action="register.php"]
[input name="login id" type="text"
value="loginid" size="20"/][br]
[input name="password" type="text"
value="password" size="20"/][br]
[input name="email" type="text"
value="email" size="50"/][br]
[input type="submit" name="submit"
value="submit"/]
[input type="reset" name="reset"
value="reset"/]
[/form]
The following code extract can also be used as part
of register.php to process the registration. The code
connects to the MySQL database and inserts a line
of data into the table used to store the registration
information.
@mysql_connect("localhost", "mysql_login",
"mysql_pwd") or die("Cannot connect
to DB!");
@mysql_select_db("tbl_login") or die("Cannot
select DB!");
$sql="INSERT INTO login_tbl (loginid, password
and email) VALUES (".$loginid.",".$password.",".$email.")";
$r = mysql_query($sql);
if(!$r) {
$err=mysql_error();
print $err;
exit();
}
The code extract assumes that the MySQL table that
is used to store the registration data is named tbl_login
and contains 3 fields - the loginid, password and
email fields. The values of the $loginid, $password
and $email variables are passed in from the form in
register.html using the post method.
Component 2: Verification and authentication of the
user.
In this the HTML form typically contains 2
fields and 2 buttons:
1. A login id field
2. A password field
3. A Submit button
4. A Reset button
Assume that such a form is coded into a file named
authenticate.html. The following HTML code extract
is a typical example. When the user has filled in
all the fields, the authenticate.php page is called
when the user clicks on the Submit button.
[form name="authenticate" method="post"
action="authenticate.php"]
[input name="login id" type="text"
value="loginid" size="20"/][br]
[input name="password" type="text"
value="password" size="20"/][br]
[input type="submit" name="submit"
value="submit"/]
[input type="reset" name="reset"
value="reset"/]
[/form]
The following code extract can be used as part of
authenticate.php to process the login request. It
connects to the MySQL database and queries the table
used to store the registration information.
@mysql_connect("localhost", "mysql_login",
"mysql_pwd") or die("Cannot connect
to DB!");
@mysql_select_db("tbl_login") or die("Cannot
select DB!");
$sql="SELECT loginid FROM login_tbl WHERE loginid='".$loginid."'
and password='".$password."'";
$r = mysql_query($sql);
if(!$r) {
$err=mysql_error();
print $err;
exit();
}
if(mysql_affected_rows()==0){
print "no such login in the system. please try
again.";
exit();
}
else{
print "successfully logged into system.";
//proceed to perform website's functionality - e.g.
present information to the user
}
As in component 1, the code excerpt assumes that
the MySQL table that is used to store the registration
data is named tbl_login and contains 3 fields - the
loginid, password and email fields. The values of
the $loginid and $password variables are passed in
from the form in authenticate.html using the post
method.
Component 3: When the user forgets his logion password
this 3rd component sends his password to the users
registered email address.
The HTML form typically contains 1 field and
2 buttons:
„h A login id field
„h A Submit button
„h A Reset button
Assume that such a form is coded into a file named
forgot.html. The following HTML code excerpt is a
typical example. When the user has filled in all the
fields, the forgot.php page is called when the user
clicks on the Submit button.
[form name="forgot" method="post"
action="forgot.php"]
[input name="login id" type="text"
value="loginid" size="20"/][br]
[input type="submit" name="submit"
value="submit"/]
[input type="reset" name="reset"
value="reset"/]
[/form]
The following code excerpt can be used as part of
forgot.php to process the login request. It connects
to the MySQL database and queries the table used to
store the registration information.
@mysql_connect("localhost", "mysql_login",
"mysql_pwd") or die("Cannot connect
to DB!");
@mysql_select_db("tbl_login") or die("Cannot
select DB!");
$sql="SELECT password, email FROM login_tbl WHERE
loginid='".$loginid."'";
$r = mysql_query($sql);
if(!$r) {
$err=mysql_error();
print $err;
exit();
}
if(mysql_affected_rows()==0){
print "no such login in the system. please try
again.";
exit();
}
else {
$row=mysql_fetch_array($r);
$password=$row["password"];
$email=$row["email"];
$subject="your password";
$header="from:you@yourdomain.com";
$content="your password is ".$password;
mail($email, $subject, $row, $header);
print "An email containing the password has
been sent to you";
}
As in component 1, the code excerpt assumes that
the MySQL table that is used to store the registration
data is named tbl_login and contains 3 fields - the
loginid, password and email fields. The value of the
$loginid variable is passed from the form in forgot.html
using the post method.
This is how a basic login system can be created.
The software developer can include additional tools
like password encryption, access to the user profile
in case they wish to edit their profile etc.
This article has been compiled by the content development
team at Pegasus InfoCorp which pulls subject matter
specialists from different work domains. They can
be contacted through the Pegasus InfoCorp website
at info@pegasusinfocorp.com. Pegasus InfoCorp is an
India based web design, web development and online/offline
software development company. Please visit http://www.pegasusinfocorp.com
to read more articles and know more about us!
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