Chartjs-Ajax reload data chat.js showing error on mouse hover on graph

I suggest you to have different name for canvas and your doughnut-chart. If you keep your doughnut-chart name as “myChart”,try:

function piechart(){
myChart.destroy();
// Pie chart or doughnut chart with chart.js

You can use the following code:

$('#myChart').replaceWith('<canvas id="myChart" width="600" height="400"></canvas>');