You can use 2 way to get data from db by using js;
1. Ajax:
function refresh() {
$.ajax({
url:"your url",
method: "GET",
data: your_params,
success: function(response) {
$("#specific_div_id").html(response);
}
});
}
You can do this within an interval like;
setInterval(refresh, 5000);
in order to get content in every 5 sec.
2. Websockets
In AJAX, you are requesting in every 5 secs to get updated content from server. Think that, you are not getting content server pushes updated content to you. In other words, server notifies you on any updated data. You can have a look at Socket.io for an example implementation of websockets. When server notifies you, you can take data and put it related html area