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Chartjs - Retrieving data from a database using mysql and php

I am trying to convert static data to database results. I will be using mysql and php.

This is the example code I have

    var randomScalingFactor = function(){ return Math.round(Math.random()*100)};
    var lineChartData = {
        labels : ["January","February","March","April","May","June","July"],
        datasets : [
            {
                label: "My First dataset",
                fillColor : "rgba(220,220,220,0.2)",
                strokeColor : "rgba(220,220,220,1)",
                pointColor : "rgba(220,220,220,1)",
                pointStrokeColor : "#fff",
                pointHighlightFill : "#fff",
                pointHighlightStroke : "rgba(220,220,220,1)",
                data : [randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor()]
            },
            {
                label: "My Second dataset",
                fillColor : "rgba(151,187,205,0.2)",
                strokeColor : "rgba(151,187,205,1)",
                pointColor : "rgba(151,187,205,1)",
                pointStrokeColor : "#fff",
                pointHighlightFill : "#fff",
                pointHighlightStroke : "rgba(151,187,205,1)",
                data : [randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor()]
            }
        ]
    }
window.onload = function(){
    var ctx = document.getElementById("canvas").getContext("2d");
    window.myLine = new Chart(ctx).Line(lineChartData, {
        responsive: true
    });
}

Below is my php / msql

$result = mysql_query("SELECT COUNT(*) FROM customer WHERE month='january'") or die(mysql_error());
$row1 = mysql_fetch_array( $result );

$result = mysql_query("SELECT COUNT(*) FROM customer WHERE month='february'") or die(mysql_error());
$row2 = mysql_fetch_array( $result );

$result = mysql_query("SELECT COUNT(*) FROM customer WHERE month='march'") or die(mysql_error());
$row3 = mysql_fetch_array( $result );

How can I use these counts from my mysql query and implement it for datasets in charts? I would also like the labels to be generated from my mysql query. Should I loop over datasets inside jquery code?

This is the plugin I use: http://www.chartjs.org/docs/#line-chart-introduction

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2 answers


Place your php code in another file named api.php

and use $.ajax

to get this data in JSON format . To convert data to JSON data, you must use json_encode()

php.

I have installed an example example, you can see here .

Please see example code:



  • api.php

    $arrLabels = array("January","February","March","April","May","June","July");
$arrDatasets = array('label' => "My First dataset",'fillColor' => "rgba(220,220,220,0.2)", 'strokeColor' => "rgba(220,220,220,1)", 'pointColor' => "rgba(220,220,220,1)", 'pointStrokeColor' => "#fff", 'pointHighlightFill' => "#fff", 'pointHighlightStroke' => "rgba(220,220,220,1)", 'data' => array('28', '48', '40', '19', '86', '27', '90'));

$arrReturn = array(array('labels' => $arrLabels, 'datasets' => $arrDatasets));

print (json_encode($arrReturn));

  • example.html

    $.ajax({
type: 'POST',
url: 'api.php',
success: function (data) {
lineChartData = data;//alert(JSON.stringify(data));
var myLine = new Chart(document.getElementById("canvas").getContext("2d")).Line(lineChartData);

var ctx = document.getElementById("canvas").getContext("2d");
window.myLine = new Chart(ctx).Line(lineChartData, {responsive: true});
} 
});

Note that you must pass the value randomScalingFactor()

to api.php

.

Please check and let me know if you need more help.

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First get the data into suitable data structures using PHP

$months = array("january", "february", "march", "april", "may", "june", "july", "august", "september", "october", "november", "december");
$monthvalues = array();
foreach ($months as $month) {
    $monthvalues[$month] = 0;
}

$result = mysql_query("SELECT month, count(*) FROM customer group by month") or die(mysql_error());
while ($row = mysql_fetch_array($result, MYSQL_NUM)) {
    $monthvalues[$row[0]] = (int)$row[1];
}

Below, just connect these data structures to your Javascript



var randomScalingFactor = function(){ return Math.round(Math.random()*100)};
var lineChartData = {
    labels : <?=json_encode($months);?>,
    datasets : [
        {
            label: "My First dataset",
            fillColor : "rgba(220,220,220,0.2)",
            strokeColor : "rgba(220,220,220,1)",
            pointColor : "rgba(220,220,220,1)",
            pointStrokeColor : "#fff",
            pointHighlightFill : "#fff",
            pointHighlightStroke : "rgba(220,220,220,1)",
            data : <?=json_encode(array_values($monthvalues));?>
        }
    ]
}

assuming window.onload and HTML for the canvas element are in their respective locations.

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