PHP Session变量未保存

Question

I've looked through all the problems about the session variable not saving and don't see my problem so I'm going to ask it.

I have a form that once submitted it searches my database for that name. The initial form is on page 1. On page 2 I take the the variable from page 1 and save it like this

    $searchTerm = $_POST['find'];

which is used as the search for the database and it works perfectly. Under that I have my sql statement then I have placed this

    //initialize the session
    if (!isset($_SESSION)) {
      session_start();
    }
    $_SESSION['searchTerm'] = $searchTerm;

I have then tested the $_SESSION['searchTerm'] on page 2 to make sure that it is saving properly, and it does. My issue comes in when I try to go to a 3rd page that is a confirm page for the form from page 2. I have the session start clause at the top of the 3rd page and I even inserted

ini_set('display_errors',1); 
error_reporting(E_ALL); 

to check for errors, no errors were displayed. So my next step was to test the session itself to see if it was refreshing the session id. I found a script on this site www.webassist.com/forums/posts.php?id=5735 to test whether the server could possibly be causing the issue. The script works fine no problems, showing that the server is not the problem. However when I upload my 2nd and 3rd page to the server and put in

    <?php echo session_id(); ?>

the numbers from page 2 and page 3 are completely different therefore making my variable null. I did further research and thought it might be because there was a session_destroy or session_unset but I didn't put one of these on either page. When I tried this on my local machine I got the same session id but still the session variable I set was blank.

Does anyone have any other ideas on how or why this would happen?

**********edit *********************

page 1 has this form

                <form name="search" method="post" action="page2.php">
                    <div>
                    <!-- Search-->
                    <label>Search by Last Name:</label>
                        <div>
                            <table width="100%">
                                <tr>
                                    <td><input type="text" id="" name="find" placeholder=""></td>
                                    <td><button id="submit" type="submit"><span>Search</span></button></td>
                                </tr>
                            </table>
                        </div>
                    </div>
                </form> 

page 2

    $searchTerm = $_POST['find'];


    if(!empty($searchTerm ) && ctype_alpha($searchTerm ))
    {
    $whereclause = "WHERE mytable.lastName = '".$searchTerm ."'";
    }
    else {
    $whereclause = "";
    }

    // sql query is here this one searches it is long and just used the $whereclause above.

    // second sql query that is only submitted if button from the form below is hit is here.

    $insertGoTo = "confirmPage3.php";
      if (isset($_SERVER['QUERY_STRING'])) {
        $insertGoTo .= (strpos($insertGoTo, '?')) ? "&" : "?";
        $insertGoTo .= $_SERVER['QUERY_STRING'] ;

      }
      header(sprintf("Location: %s", $insertGoTo));

    //initialize the session
    if (session_id() == '') {
      session_start();
    }
    $_SESSION['searchTerm'] = $searchTerm;


    // then the form is listed below that with the rest of the html 

page 3

    <?php if(session_id() == '') session_start(); ?> 

    if(!empty($_SESSION['searchTerm']) && ctype_alpha($_SESSION['searchTerm']))
    {
    $whereclause = "WHERE myTable.lastName = '".$_SESSION['searchTerm'] ."'";
    }
    else {
    $whereclause = "";
    }

    // More sql statement here for this one it is only selecting not updating or changing anything.

    // Table below this that is used to hold the items retrieved from the database.

***********edit 2 and my fix**********

so after some back and for with a few of you, Aaron Gong suggested I start with a blank page and go from there. I did this and have finally diagnosed the issue. It was something that I hadn't thought of that I very well should have. I don't like using dreamweaver and now I remember why. When I originally created the page 2 I used dreamweavers insert code to insert my sql statement to do the updating. Well it placed in the code these lines of code.

    $editFormAction = $_SERVER['PHP_SELF'];
    if (isset($_SERVER['QUERY_STRING'])) {
      $editFormAction .= "?" . htmlentities($_SERVER['QUERY_STRING']);
    }

This will completely mess with you if you are trying to send the user to another page to confirm their entries. I commented it out and set the $editFormAction to my page and used that in the header string and viola that immediately fixed my issue. What I hadn't realized is when it was refreshing the page that it was emptying my $_POST variable and found that error finally through the empty pages suggest by Aaron.

Hope this helps someone else and I will never trust the code from dreamweaver again. I learned to code by hand and should know better but I was in a hurry and thought oh it won't harm it.

Thanks again to all your suggestions.

Answer 1

Not sure what your 3rd page looks like but mine would be:

session_start(); // Use session variable on this page. This function must put on the top of page.

if( isset($_SESSION['i_am_in']) ) echo "logged in";

My Page 2:

if ($login_ok) {
    session_start(); // Create session & settings
    $_SESSION['abc123'] = 'whatever';
    header('Location: page3.php');
}