PHP Learning Cookie Session Control

The use of cookies to record user data on the client without the need to call from the server every time, this can improve the efficiency of the Web page, reduce the pressure on the server

The following example simulates the operation of a login interface, using the invocation of a cookie

Interface display (not beautified)

Create the required files under the root directory

index.ph In p , the output of the tabular form is first written out

Create a database and create a file that is called by the database because you want to connect to the database and call the database's data
Create a table of users and insert data, where data is inserted into information including user name, password, and permissions

Create a conn.inc.php in the root directory to hold the database connection

conn.inc.php
<?php    $mysqli =new mysqli ("localhost", "root", "XXXXX", "sqldb");

connection database included in login.php, using the Mysqli method, the password is encrypted using the MD5 () method
<?php    if (isset ($_post["sub")) {    include "conn.inc.php";    $sql = "SELECT id from users where name= ' {$_post[" name "]} ' and password= '". MD5 ($_post["password"]). "'";    $result = $mysqli->query ($sql);    Save Data    if ($result->num_rows > 0) {    $row = $result->fetch_assoc ();    $time =time () *1800;    Setcookie ("username", $_post["name"], $time);    Setcookie ("UID", $row ["id"], $time);    Setcookie ("IsLogin", 1);    Header ("Location:index.php");  Jump interface    }    echo "username password wrong";    }? >

Note that the cookie needs to indicate the length of time the data is saved, "username", "uid", "IsLogin" in the saved data
Index.php involves page jumps, creating a common jump page for the class comm.php
comm.php: If the return is "IsLogin" to jump
<?php    //judgment: If not logged in automatically jump to the login page if    (!$_cookie["IsLogin"]) {        header ("Location:login.php");    }

Log in successfully after the jump to the index.php page, login is unsuccessful, return to log in again
index.php contains conn.inc.php and comm.php
<?php    include "comm.php";  Determine if login success    include "conn.inc.php";    echo "User <b>". $_cookie["username"]. " </b> Hello! This is the homepage of the website ";    echo "Your permission is as follows:<br>";    $sql = "Select Allow_1,allow_2,allow_3,allow_4 from Users where id= ' {$_cookie[" UID "]} '";    $result = $mysqli->query ($sql);    $user = $result->fetch_assoc ();    if ($user ["Allow_1"]) {        echo "111111111111<br>";    }    if ($user ["allow_2"]) {        echo "222222222222<br>";    }    if ($user ["Allow_3"]) {        echo "333333333333<br>";    }    if ($user ["Allow_4"]) {        echo "444444444444<br>";    }    ? >    <a href= "test.php" > second page </a><br>    <a href= "test2.php" > third page </a><br >    <a href= "logout.php" > Exit </a><br>
The last second page and the third page are the same as index.php.
Logout logout.php need to log out user information
<?php    include "comm.php";  Determine if the login is successful        $username =$_cookie["username"];  Remove username    //logout    Setcookie ("username");    Setcookie ("UID");    Setcookie ("IsLogin");    echo $username. " Goodbye ";? ><br><a href= "login.php" > re-login </a>




Full code:
login.php:
<?php if (Isset ($_post["sub")) {include "conn.inc.php";    $sql = "SELECT id from users where name= ' {$_post[" name "]} ' and password= '". MD5 ($_post["password"]). "'";    $result = $mysqli->query ($sql);    Save data if ($result->num_rows > 0) {$row = $result->fetch_assoc ();    $time =time () *1800;    Setcookie ("username", $_post["name"], $time);    Setcookie ("UID", $row ["id"], $time);    Setcookie ("IsLogin", 1);  Header ("Location:index.php");    Jump interface} echo "User name password is incorrect"; }?>

















PHP Learning Cookie Session Control