Populate group data to a particular series on Highcharts - php

Question

Trying to group tow columns and and populate it as a particular series on highcharts. my code not grouping columns, And showing all data as a single series.
$query = $db->Prepare("SELECT class, SUM(marks), DATE(date_column) as
dates FROM classes GROUP BY class,DATE(date_column)");
$query->execute();
while ( $row = $query->fetch(PDO:: FETCH_ASSOC)) {
$date = $row['dates'];
$dates[] = $row['dates'];
$class[] = $row['class'];
$marks[] = $row['SUM(marks)'];
$output[] = array($date,(int)$marks);
}
echo json_encode(array('date'=>$dates,'marks'=>$marks, 'name' => $class));
JS
<script>
$(document).ready(function () {
$(function() {
$.getJSON('data.php', function(data) {
// Create the chart
Highcharts.chart('container', {
title: {
text: 'class Marks'
},
xAxis: {
categories: data.dates
},
series : [{
"name" : data.name,
"data": data.marks
}],
});
});
});
});
</script>
Table
Expected output in JSFiddle
data response
date: ["2019-02-07", "2019-02-09", "2019-02-12", "2019-02-08", "2019-02-12",
"2019-02-13", "2019-03-13",…]
marks: ["45", "166", "78", "64", "64", "627", "87", "352"]
name: ["claas 1", "claas 1", "claas 1", "class 2", "class 2", "class 2", "class 3", "class 3"]

Answer 1

By seeing your fiddle the expected output you want for HighCharts is as follow:
1: Category Data:
It should be an array of dates.
Make sure you remove duplicates and order them in ascending/descending order whichever you want, to see a continuous graph.
"categories":["2019-02-07", "2019-02-08", "2019-02-09", "2019-02-12", "2019-02-13", "2019-02-14"]
2: Series Data:
It would be an array of object, where each object contains two properties name and data.
Data should have n no of values if your categories array has n values and each corresponds to same index.
As we don't have data for each date for each class, we would add 0 there.
So data would look like
"series":[
{
"name":"class 1",
"data":[45,0,166,78,0,0]
},
{
"name":"class 2",
"data":[0,64,0,64,627,0]
},
{
"name":"class 3",
"data":[0,0,0,0,87,352]
}
]
Final Fiddle which can be achieved by PHP using below code:
$arrDates = [];
$arrClass = [];
$arrData = [];
while ( $row = $query->fetch(PDO:: FETCH_ASSOC)) {
$arrDates[] = $row['dates'];
$arrClass[] = $row['class'];
$arrData[$row['class'] . ':' . $row['dates']] = $row['marks']; // to identify for which date & class this marks belong to, we can directly search for index.
}
$arrDates = array_unique($arrDates);
sort($arrDates);
$arrClass = array_unique($arrClass);
// Create series data
$arrSeriesData = [];
foreach($arrClass as $strClass){
$tempArr = ['name' => $strClass];
foreach($arrDates as $strDate){
$tempArr['data'][] = isset($arrData[$strClass . ':' . $strDate]) ? intval($arrData[$strClass . ':' . $strDate]) : 0;
}
$arrSeriesData[] = $tempArr;
}
$response = ['categories' => $arrDates, 'series' => $arrSeriesData];
echo json_encode($response);
Output:
{"categories":["2019-02-07","2019-02-08","2019-02-09","2019-02-12","2019-02-13","2019-02-14"],"series":[{"name":"class 1","data":[45,0,166,78,0,0]},{"name":"class 2","data":[0,64,0,64,627,0]},{"name":"class 3","data":[0,0,0,0,87,352]}]}
Update your javascript code to reflect the above
$(document).ready(function() {
$(function() {
$.getJSON('data.php', function(data) {
// Create the chart
Highcharts.chart('container', {
title: {
text: 'class Marks'
},
xAxis: {
categories: data.categories
},
series: data.series,
});
});
});
});