[FIXED] Change query or data with foreach loop

Issue

I am trying to make my data by passing an exam id... the numbers are my student numbers. The data is stored in my db like this..

Here is my php code

$sql = "SELECT number, question_id, answer FROM `questions_answers` WHERE exam_id=" . $id;

$command = Yii::app()->db->createCommand($sql);
$data = $command ->query();

This is my for each loop, i am writing to csv file.

foreach($data as $result) {
   fwrite($fp, $result['number'] . "," . $result['answer'] . "\r\n");          
}

This is giving me result like this..

I want my result to be like this.. Where 2 is the answer of Q1 giving by number 3100000123, then 3 is answer of Q2, 1 is answer of Q3. Similarly for next student number.. I have tried different things but none of them worked for me. How can i achieve my data like this?

Solution

Try this way:

$newArr = array();
foreach($data as $result) {
    $newArr[$result['number']][] = $result['answer'];
}

foreach($newArr as $number=>$answer) {  
    $answer_sring = implode(",",$answer);
    fwrite($fp, $number . ", ".$answer_sring. "\r\n");                  
}

Answered By - Ahmed Ginani