How to store data in php

How to store data in session in php

Solution 3: Try this.. echo session create session in php session start php Question: I want to use session values in my script which are stored at the server using php can any one kindly explain the process to achieve this. Notice that Session variables are not passed individually to each new page, instead they are retrieved from the session we open at the beginning of each page ( ).

PHP Sessions

A session is a way to store information (in variables) to be used across multiple pages.

Unlike a cookie, the information is not stored on the users computer.

What is a PHP Session?

When you work with an application, you open it, do some changes, and then you close it. This is much like a Session. The computer knows who you are. It knows when you start the application and when you end. But on the internet there is one problem: the web server does not know who you are or what you do, because the HTTP address doesn’t maintain state.

Session variables solve this problem by storing user information to be used across multiple pages (e.g. username, favorite color, etc). By default, Session variables last until the user closes the browser.

So; session variables hold information about one single user, and are available to all pages in one application.

Tip: If you need a permanent storage, you may want to store the data in a database.

Start a PHP Session

A session is started with the session_start() function.

Session Variable s are set with the PHP global variable : $_SESSION.

Now, let’s create a new page called «demo_session1.php». In this page, we start a new PHP Session and set some session variable s:

Example

Note: The session_start() function must be the very first thing in your document. Before any HTML tags.

Get PHP Session Variable Values

Next, we create another page called «demo_session2.php». From this page, we will access the session information we set on the first page («demo_session1.php»).

Notice that Session variable s are not passed individually to each new page, instead they are retrieved from the session we open at the beginning of each page ( session_start() ).

Also notice that all session Variable Values are stored in the global $_SESSION variable :

Example

// Echo session variables that were set on previous page
echo «Favorite color is » . $_SESSION[«favcolor»] . «.
«;
echo «Favorite animal is » . $_SESSION[«favanimal»] . «.»;
?>

Another way to show all the session variable values for a user session is to run the following code:

Example

How does it work? How does it know it’s me?

Most sessions set a user-key on the user’s computer that looks something like this: 765487cf34ert8dede5a562e4f3a7e12. Then, when a session is opened on another page, it scans the computer for a user-key. If there is a match, it accesses that session, if not, it starts a new session.

Modify a PHP Session Variable

To change a session variable, just overwrite it:

Example

// to change a session variable, just overwrite it
$_SESSION[«favcolor»] = «yellow»;
print_r($_SESSION);
?>

Destroy a PHP Session

To remove all global session variables and destroy the session, use session_unset() and session_destroy() :

Example

PHP Exercises

PHP Sessions, Start a PHP Session. A session is started with the session_start () function. Session variables are set with the PHP global variable: $_SESSION. Now, let’s create a new page called «demo_session1.php». In this page, we start a new PHP session and set some session variables: echo «Session variables are set.»; Code samplesession_start();?>Feedback

How to store a variable in php using session

i want to store a value in to session using PHP

for example $id=10 i want to store this value in a session

$pid= session_id($id); echo $pid; 

then to set session variable

To retrieve the value of id

Further more read more about session here

Here is the right code to store the variable in PHP session :

Now to get the session data:

Also, I have write a complete guide on php session on one of my blog: How to start a PHP session, store and accessing Session data?

How to store a variable in php using session, Teams. Q&A for work. Connect and share knowledge within a single location that is structured and easy to search. Learn more

How to store data in session in php

echo session

create session in php

session start php

Session value store in php Code Example,

How To get all the session values stores at the server using php

I want to use session values in my script which are stored at the server using php can any one kindly explain the process to achieve this.

I want to build a chat app for this am planning to use those session values.

Assume usera and userb are logged in and their userid is sessioned based on this scenario i want to do a chat app.

Now i had done the app but i had used setinterval function of Javascript and am calling the chats i want to avoid the database hits on every 3 mill sec.

You’re basically attempting to use PHP session files as a file cache .

Instead, you should use an object caching system such as Memcached or Redis. If memory caching isn’t an option (shared hosting, etc), then you could implement your own file cache (or you could use something like PHPFastCache, which supports file caching).

Note: File caching for a chat app may or may not speed up your application. It depends on how you implement it and a number of other factors.

Hi put the session value in input box, '> Using the id fetch the session value in script,  

3ms is insanely short delay to run a polling chat system. I suggest increasing it to at least 200ms but preferably around 1000ms.

$_SESSION values are per user and not recommended for viewing a chat stream for a number of reasons. Instead it sounds like you are looking more to just update the chat feed.

The database unless it is hosted on another server and $_SESSION will be the equivalent, since the database is effectively files as well. The database will actually generally be faster than reading raw file storage since Queries are normally cached and Indexing helps lookup records quicker. In addition you won’t have to worry about concurrent connections to the files either.

If anything enable OPCache and install APCu for your PHP installation, to help aid the serving of requests. OPCache will cache your compiled OP code into memory so that subsequent requests to the file won’t need to be recompiled. APCu will act as your file cache, again storing your rendered data in memory. Additionally many Database Frameworks such as Doctrine can also utilize APC caching for query and result caching.

Instead of using a InnoDB or MyISAM storage engines for your chat messages I suggest trying the MEMORY storage engine. So instead of accessing the File System I/O your database would instead be utilizing the Memory I/O. The general concept is few writes, many reads. Since one person writes to the database, requires everyone to read the data. Just keep in mind that the Memory storage engine is temporary and is lost if the server restarts or power is lost.

For more information see: https://dev.mysql.com/doc/refman/5.6/en/memory-storage-engine.html

Overall if you are able, I would suggest look at using Socket IO (Websockets) instead of either database or file based caching. This puts the load on the clients instead of the server, and everything occurs in real-time instead of polling for changes.

1. Ratchet http://socketo.me/
2. React http://reactphp.org/
3. Node.js http://tutorialzine.com/2014/03/nodejs-private-webchat/

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How to Use PHP Sessions to Store Data

Sometimes it’s necessary for you to temporarily store data specific to a particular user while he/she surfs your website. For example, you may want to store that user’s preferences or the secret word displayed in a CAPTCHA image for checking later. PHP sessions provide you with just such a facility.

What’s the Difference Between Storing Data in Cookies and Session Variables?

If you have read my tutorial on How to Create and Use Cookies in PHP, you may be wondering why you might want to bother with sessions when you can already use cookies to store small amounts of data specific to a particular user.

There are undoubtedly a number of differences between the use of cookies and session data. The following are, to me, the most significant difference that will affect your choice of which to use.

1. Cookies are returned and stored in the user’s browser, session data is stored on your web server.
2. The life span of a cookie can be set to almost any duration of your choosing. PHP sessions have a predetermined short life. The exact life span depends on how your web host has configured PHP on your server.
3. Depending on how your web server is configured, session data is often stored in a public temporary directory on the server. As such it is possible that other users on the server may be able to peek at the data you store there.

When to Use Sessions Rather than Cookies

The above differences affect your choice of whether you should use cookies or sessions to store your data. Note that the following list is not exhaustive.

When you need the data stored on the server and not your user’s browser

When the data is transient, and only relevant for the current browsing session

When the data does not contain any information that needs to be securely kept

How to Use Sessions in Your PHP Scripts

To use sessions in your script you need to do the following.

Starting a Session

Storing and Accessing Variables

To store variables relevant to the session, assign what you want to a member of the $_SESSION array. For example, the following snippet assigns «ABC123» to $_SESSION[«secretword»] and a colour to $_SESSION[«theme»] :

You can assign as many variables as you wish. To access those variables, simply reference it as you would any PHP array. For example:

session_start();
$captcha = $_POST[«captcha»] ;
$secretword = $_SESSION[«secretword»] ;

if (strcmp( $captcha, $secretword )) // it’s a bot
>
else // matched — it’s a human
>

Ending a Session

Conclusion

With this introduction to PHP sessions, you should be able to code scripts that take advantage of the built-in session handling provided by PHP.

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Copyright © 2008-2014 by Christopher Heng. All rights reserved.
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This page was last updated on 5 June 2014.

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