在beforeunload事件中查询数据库

Question

I was wondering if its possible to send a query to the database on the beforeunload event.

$(window).on('beforeunload',function() {
    console.log('beforeunload called. run query');
});

If so, how would I do it? I need to run a query to insert dynamic values into the database.

Answer 1

You could try this, but beware that the onbeforeunload event is limited for certain browsers..

window.onbeforeunload = mySession;
function mySession(){
    $.ajax({
        url: "/../../myPHP.php",
        async: false,
        type: "GET"
    });
    return "WhatEverMessageYouFeelLike";
}

and your PHP executing query from AJAX handling..

$delete = "DELETE FROM MyTable WHERE id=" .$_SESSION['mySessionVariable'];
// your query..

Answer 2

Use a jQuery AJAX call. Assuming you're POSTing your data, try this:

$.post(
    'your/url',
    {
        your : "Post Vars"
    },
    function(data) {
        // not sure if you'll need to do anything here actually.
    },
    'json' // or 'html', or whatever you want your return format to be
);

Answer 3

I thinks the best way to use post by jQuery is $.post() method.but u can also use $.ajax

Sample way to use is

jQuery

$.post( "ajax/test.html", function( data ) {
  $( ".result" ).html( data );
});

jQuery Ajax

$.ajax({
  type: "POST",
  url: url,
  data: data,
  success: success,
  dataType: dataType
});