Create javascript array from php sql query for use with charts.js

Have you tried

echo "var data = " . json_encode($rows .';');

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This might not work because the JSON structure that is output might not match what you are expecting in your JavaScript code in which case you might have to massage your PHP data.

What does your data look like in $rows - can you var_dump / print_r it so we can have a look.

This is what I get returned:

Array ( [0] => Array ( [questionOptionID] => 60 [questionID] => 29 [questionOption] => Queen Mary [correctAnswer] => 1 [questionResponseCount] => 6 ) [1] => Array ( [questionOptionID] => 61 [questionID] => 29 [questionOption] => Queen Boudica [correctAnswer] => 0 [questionResponseCount] => 36 ) [2] => Array ( [questionOptionID] => 62 [questionID] => 29 [questionOption] => Queen Matilda [correctAnswer] => 0 [questionResponseCount] => 8 ) [3] => Array ( [questionOptionID] => 63 [questionID] => 29 [questionOption] => Queen Elizabeth I [correctAnswer] => 0 [questionResponseCount] => 3 ) )

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and I need questionOption and questionResponseCount.

Here is a example for you,

<?php
$months=array("Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec");
$datasets = array(
  "dataset"=> array(
    array("data" => array (10,110,210,310,410,510), 
      "label" => "My First dataset",
      "fillColor"=> "rgba(220,220,220,0.5)",
      "strokeColor"=> "rgba(220,220,220,0.8)",
      "highlightFill"=> "rgba(220,220,220,0.75)",
      "highlightStroke"=> "rgba(220,220,220,1)"),  
    array("data" => array (20,120,220,320,420,520),
      "label"=> "My Second dataset",
      "fillColor"=> "rgba(220,220,220,0.5)",
      "strokeColor"=> "rgba(220,220,220,0.8)",
      "highlightFill"=> "rgba(220,220,220,0.75)",
      "highlightStroke"=> "rgba(220,220,220,1)"),  
    array("data" => array (30,130,230,330,430,530),
      "label"=> "My Third dataset",
      "fillColor"=> "rgba(220,220,220,0.5)",
      "strokeColor"=> "rgba(220,220,220,0.8)",
      "highlightFill"=> "rgba(220,220,220,0.75)",
      "highlightStroke"=> "rgba(220,220,220,1)")
    )
);

$jsonArray = array("months"=> $months, "datasets"=> $datasets);
echo json_encode($jsonArray,JSON_PRETTY_PRINT);
?>

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You have to pick appropriate sql query/data columns for each data values

Here is an another example, showing how to build array and then output the json

            

$mydata = array(
  array("questionOptionID" => 10, "questionID" => 19,"questionOption" => "Question Option 1", "correctAnswer" => 1,"questionResponseCount" => 6),
  array("questionOptionID" => 20, "questionID" => 29,"questionOption" => "Question Option 2", "correctAnswer" => 1,"questionResponseCount" => 10),
  array("questionOptionID" => 30, "questionID" => 39,"questionOption" => "Question Option 3", "correctAnswer" => 2,"questionResponseCount" => 30),
  array("questionOptionID" => 40, "questionID" => 49,"questionOption" => "Question Option 4", "correctAnswer" => 3,"questionResponseCount" => 100),
  array("questionOptionID" => 50, "questionID" => 59,"questionOption" => "Question Option 5", "correctAnswer" => 3,"questionResponseCount" => 20)
);

echo json_encode($mydata,JSON_PRETTY_PRINT);

$qdata1 = array();
$qdata2 = array();

foreach ($mydata as $qdata) {
  echo "<h3>" .  $qdata['questionOption'] . ":" . $qdata['questionResponseCount'] .  "</h3>";
  array_push($qdata1,$qdata['questionOption']);
  array_push($qdata2,$qdata['questionResponseCount']);
}

$jsonArray = array(
  "labels"=> $qdata1, 
  "datasets"=> array(
  "data"=>$qdata2,
  "label"=> "My Third dataset",
  "fillColor"=> "rgba(220,220,220,0.5)",
  "strokeColor"=> "rgba(220,220,220,0.8)",
  "highlightFill"=> "rgba(220,220,220,0.75)",
  "highlightStroke"=> "rgba(220,220,220,1)")
);

echo json_encode($jsonArray,JSON_PRETTY_PRINT);

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Firstly, not sure how the data dump you posted ties into Chart.js - did you dump the correct data? The data looks like a question structure for a survey type application.

Here is some sample code for how to get the Array data you posted into a JavaScript array - you can adapt if necessary

<!doctype html>
<html>
<body>
<?php
$rows = array ( 
array ( 
	'questionOptionID' => 60,
	'questionID' => 29, 
	'questionOption' => "Queen Mary", 
	'correctAnswer' => 1, 
	'questionResponseCount' => 6
	), 
array ( 
	'questionOptionID' => 61,
	'questionID' => 29, 
	'questionOption' => "Queen Boudica",
	'correctAnswer' => 0, 
	'questionResponseCount' => 36 
),
array ( 
	'questionOptionID' => 62, 
	'questionID' => 29, 
	'questionOption' => "Queen Matilda",
	'correctAnswer' => 0, 
	'questionResponseCount' => 8 
), 
array ( 
	'questionOptionID' => 63, 
	'questionID' => 29, 
	'questionOption' => "Queen Elizabeth I", 
	'correctAnswer' => 0, 
	'questionResponseCount' => 3 
	) 
);
$json = json_encode($rows);
echo $json;
echo <<< JSCRIPT
<script>
	var questions={$json};
</script>
JSCRIPT;
?>
<script>
console.log(questions);
</script>
</body>
</html>

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Working sample here. Examine the console to see the output of the console.log(questions) that dumps the JavaScript array created by the PHP script.