Chart.js - Getting data from database using mysql and php

Question

I'm trying to convert the static data to using database results. I'll be using MySQL and PHP.

Example Code:

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 could I use those count() from my MySQL query and implement it to datasets on chartjs? I would also like the labels to be generated from my MySQL query too. Should I loop the datasets inside the jQuery code?

This is the plugin that I'm using : http://www.chartjs.org/docs/#line-chart-introduction

Answer 1

First get your 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 that, just plug in those data structures into 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 the the window.onload and the HTML for the canvas element are in their proper places.