Using Sessions

[wesmith4]

See script 12.12 from the 4th edition.

This login.php script sets some session data.

on line 19-> $_SESSION['user_id'] = $data['user_id];

 

In another script I retrieve information in a query using a WHERE clause containing $_SESSION['user_id'].   But it does not work.

 

Here is some of the code:

 

</php script view students grades.

session_start();

require ('./mysqli_connect.php');

$q = "SELECT * FROM TranscriptView WHERE studentID = $_SESSION['user_id'];

$r = @mysql_query ($dbc, $q);

$num = mysqli_num_rows($r);

 

But the variable $num is not one.

The routine fails at this point

 

It is like the session variable is a string, not an integer!

 

Can anyone provide me with direction?

 

Wes Smith

 

[HartleySan]

There are several potential issues here.

To start with, your query string is not being closed by a double quote at the end.

In addition, it's usually best to enclose all array and object values being output within a string with a set of curly brackets to keep the PHP interpreter from getting confused.

 

In other words, I would change your query to the following:

$q = "SELECT * FROM TranscriptView WHERE studentID = {$_SESSION['user_id']};";

Next, I would check that the $_SESSION['user_id'] value is indeed an integer. You can use the is_int function in PHP to check that (http://php.net/manual/en/function.is-int.php).

Lastly, I'd try running the following static query from phpMyAdmin or wherever to ensure that your query is valid to begin with:

SELECT * FROM TranscriptView WHERE studentID = 1;

Please let us know what you find.

Thanks.

[wesmith4]

Here is more details about my problems using PHP sessions:

 

1  <?php # Script 10.1 - view_one_students_report_copy.php

2  // This script retrieves the grades for students.

3  session_();

4  $page_title = 'View Your Courses And Grades.';

5  // include ('includes/headerStuReport.html');

6  require ('./mysqli_connect.php');

7  echo "session number =".$_SESSION[user_id'];

8  // Define the query:

9  $q = "SELECT * FROM TranscriptView WHERE StudentID = {$_SESSION['user_id']}";

10 $r = @mysqli_query ($dbc, $q);

11

12 // Count the number of returned rows:

13 $num = mysqli_num_rows($r);

14

15 ?>

=====================================================

 

1st:  I run the query(line 9) in using PHP MYADM. There is no problem.

2nd: When I run the short code above, I get the following error:

 

Parse error: syntax error, unexpected T_CONSTANT_ENCAPSED_STRING, expecting ']' in /home/content/00/10035700/html/view_one_students_report_copy_copy.php on line 9

 

I don't understand what I am doing wrong.

Any help would be appreciated!

Wes Smith

wesmith4@gmail.com

 

[HartleySan]

The error is a bit misleading because line 7 is actually the problem.

echo "session number =".$_SESSION[user_id'];

Should be changed to:

echo "session number =".$_SESSION['user_id'];

Please notice the extra single quote before "user".