a 500 Internal Server Error occur on statisticLoadUser function

I hope this helps….

https://tutorials.ausweb.com.au/web-hosting/php-and-mysql/solving-a-500-internal-server-error.html

Dear Wisecapt,

I have look into the article and tried to find who whether there is a script error or permission issues causing this issue. Unfortunately i can’t find.

I even maximise php memory as some people to resolve,but in vain.:(

This is driving nut and i need to deliver this work by friday .Would really grateful to get some shared information on how to resolve this issue.

Thank you for responding back

Dear Wisecapt,

Where is the get_userdata found in??

In the statistic controller,function ajaxLoadStatisticUser there is this line
$userInfo = get_userdata($view->statisticModel->getUserId());
am wondering where is the implementation of this method as it take in as parameter the userid.

Is this causing the 500 error message? O.o..

Thank you once again for response

I know the code works on my server, so I do not think its a script error. Make sure you have the latest php and mysql database server.

Another thing to try is using a default wordpress theme. Sometimes themes cause a problem and its worth trying a default theme to see if the problem goes away.

Wisecapt

Dear Wisecapt,

Thank you for replying back.:)
In fact the issue is due the version of mysql version on production server which is 5.0.45 .
The php version on production server 5.2.4

On local development side, the script is working perfectly with mysql version 5.5.24 and php version 5.4.3.
When i tried to switch with php version 5.2.4 on locally it works
then i switch with mysql version 5.0.45 locally as well, then i got the same 500 Internal error .

In my firebug,

POST

Parametersapplication/x-www-form-urlencoded
action	wp_pro_quiz_admin_ajax
data[avg]	0
data[quizId]	2
data[refId]	9
data[userId]	0
func	statisticLoadUser
Source
action=wp_pro_quiz_admin_ajax&func=statisticLoadUser&data%5BquizId%5D=2&data%5BuserId%5D=0&data%5BrefId%5D=9&data%5Bavg%5D=0

RESPONSE

<div id='error'>
			<p class='wpdberror'><strong>WordPress database error:</strong> [Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause]<br />
			<code>SELECT
					sf.*,
					MIN(sf.create_time) AS min_create_time,
					MAX(sf.create_time) AS max_create_time
				FROM
					wp_wp_pro_quiz_statistic_ref AS sf
				WHERE
					sf.statistic_ref_id = 9 AND sf.quiz_id = 2</code></p>
			</div><br />
<b>Fatal error</b>:  Call to a member function getUserId() on a non-object in <b>C:\wamp\www\test\wp-content\plugins\wp-pro-quiz\lib\controller\WpProQuiz_Controller_Statistics.php</b> on line <b>701</b><br />

Thank you for you kind help.

Dear Wisecapt

Good news i resolved the issue..was turning crazy..but i think madness turns to bring buld of light on my head ??

To resolve this issue
I have change add GROUP BY sf.statistic_ref_id in the class file
named WpProQuiz_Model_StatisticRefMapper in the following function

public function fetchByRefId($refIdUserId, $quizId, $avg = FALSE) {
		$where = $avg ? 'sf.user_id = %d' : 'sf.statistic_ref_id = %d';
		$results = $this->_wpdb->get_results(
			$this->_wpdb->prepare(
				"SELECT
					sf.*,
					MIN(sf.create_time) AS min_create_time,
					MAX(sf.create_time) AS max_create_time
				FROM
					{$this->_tableStatisticRef} AS sf
				WHERE
					{$where} AND sf.quiz_id = %d
                GROUP BY sf.statistic_ref_id"
			, $refIdUserId, $quizId)
		, ARRAY_A);

		foreach ($results as $row) {
			$row['form_data'] = $row['form_data'] === null ? null : @json_decode($row['form_data'], true);

			return  new WpProQuiz_Model_StatisticRefModel($row);
		}
	}

Let’s me know about your feedback.
Take care

Dear Pretee, I had the same issue and your help solved it. Many thanks!