Reputation: 49
I am trying to fetch data from mysql database and plot a line graph using canvas.js way.....I just want to know how to pass values which I have fetched from database into the dataPoints: x and y values....i;e..X will contain Time and Y contains Temperature.I am trying to plot Time vs Temperature Graph here..
I have received these two data values from my database in php using this code.
$sql1 = "SELECT Time FROM sdata ORDER BY ID DESC LIMIT 10;";
$response1 = mysqli_query($connect, $sql1) or die(mysqli_error($connect));
while($row1 = mysqli_fetch_all($response1)){
$r1[]= $row1;
}
$sql2 = "SELECT Temperature FROM sdata ORDER BY ID DESC LIMIT 10;";
$response2 = mysqli_query($connect, $sql2) or die(mysqli_error($connect));
while($row2 = mysqli_fetch_all($response2)){
$r2[]= $row2;
}
Here when i give echo and see the r1 and r2 values I am able to see the database values....
--These are DateTime values from my database:
[[["8/30/2016 9:37"],["8/30/2016 9:33"],["8/30/2016 9:32"],["8/30/2016 9:32"],["8/30/2016 9:32"],["8/30/2016 9:32"],["8/30/2016 9:32"],["8/30/2016 9:31"],["8/30/2016 9:31"],["8/30/2016 9:31"]]]
--These are Temperature values from my database:
[[[25],[25],[28.91],[28.82],[28.84],[28.91],[29.05],[29.05],[28.92],[29.11]]]
Now i want to pass these varaibles to dataPoints: x and y as shown in below code:
<script type="text/javascript">
window.onload = function() {
var chart = new CanvasJS.Chart("chartContainer", {
title: {
text: "Line Chart"
},
axisX: {
interval: 5,
title: "Time",
valueFormatString: "hh:mm TT",
},
axisY: {
interval: 20,
title: "Temp"
},
data: [{
type: "line",
dataPoints: ???????????(HOW DO I PASS THE r1 and r2 values here for x and y respectively so that it give me a line chart is my question)
}]
});
chart.render();
}
</script>
Plz help me in this....
Upvotes: 1
Views: 1771
Reputation: 493
You need to parse data in the format which CanvasJS accepts. Check the code below
$r1=[[["8/30/2016 9:37"],["8/30/2016 9:33"],["8/30/2016 9:32"],["8/30/2016 9:32"],["8/30/2016 9:32"],["8/30/2016 9:32"],["8/30/2016 9:32"],["8/30/2016 9:31"],["8/30/2016 9:31"],["8/30/2016 9:31"]]];
$r2=[[[25],[25],[28.91],[28.82],[28.84],[28.91],[29.05],[29.05],[28.92],[29.11]]];
$dataPoints=array();
for($i=0;$i<count($r1[0]);$i++){
array_push($dataPoints,array('x'=> strtotime($r1[0][$i][0])*1000,'y'=>$r2[0][$i][0]));
}
var chart = new CanvasJS.Chart("chartContainer", {
.
.
dataPoints: <?php echo json_encode($dataPoints); ?> // edited
.
.
});
Upvotes: 3