Server-side processing default order - php

Question

I want to set the default ordering of my datatable into desc.
I tried to see the value of $request["order"][0]['dir'] it always comes up in ascending order. Is there a way to set the ordering to descending order? I have added my JS below.
$sqlRecord .= " ORDER BY ". $columns[$request['order'][0]['column']] ." " . $request["order"][0]['dir'] . " LIMIT " . $request["start"] . " ," . $request["length"]. " ";
$.ajax({
url: "coordinator-activities-table.php",
method: "POST",
success: function(data){
$("#retailer-activities-container").html(data);
table = [
{ "width": "120px", "orderable": false, "targets": 0 },
{ "width": "80px", "targets": 1 },
{ "width": "150px", "targets": 2 },
{ "width": "120px", "targets": 3 },
{ "width": "150px", "targets": 4 },
{ "width": "150px", "targets": 5 },
{ "width": "150px", "targets": 6 },
{ "width": "150px", "targets": 7 },
{ "width": "150px", "targets": 8 },
{ "width": "150px", "targets": 9 },
{ "width": "120px", "targets": 10 },
{ "width": "100px", "targets": 11 },
{ "width": "110px", "targets": 12 },
{ "width": "110px", "targets": 13 },
{ "width": "150px", "targets": 14 },
{ "width": "150px", "targets": 15 },
{ "width": "120px", "targets": 16 },
{ "width": "150px", "orderable": false, "targets": 17 }
];
var table = $('#activities-table').DataTable({
"searching": { "regex": true },
"paging": true,
"autoWidth": false,
"processing": true,
"serverSide": true,
"ajax": {
url: "coordinator-activities-data.php",
type: "POST",
"dataType": "json",
data: {coordinator:coordinator, startdate:startdate, enddate:enddate, regional:regional},
"complete": function(response) {
}
},
"columnDefs": table,
"language": {
"emptyTable": "No data available in table",
"zeroRecords": "No data available in table",
"info": "Showing <b>_START_</b> to <b>_END_ of _TOTAL_</b> entries",
"paginate": {
"first": "First",
"last": "Last",
"next": "Next",
"previous": "Previous"
},
search: "_INPUT_",
searchPlaceholder: "Search..."
},
dom: 'Bfrtip',
buttons: [
'csv', 'excel', 'pdf'
]
});
},
error: function(data){
console.log("error");
}
});
I want to set the default ordering to descending

Answer 1

You can change the Sort data when datatable makes the request to server like this :
var firstsort='DESC';
var table = $('#activities-table').DataTable({
"searching": { "regex": true },
"paging": true,
"autoWidth": false,
"processing": true,
"serverSide": true,
"ajax": {
url: "coordinator-activities-data.php",
type: "POST",
"dataType": "json",
data: function (data) {
var sort = data.order[0].column;
//check condition or remove condition if you want every request with sort DESC
if (firstsort != '') {
data.order[0].dir = "DESC";
firstsort = '';
}
data['coordinator'] = coordinator, data['regional'] = regional,
data['startdate'] = startdate, data['enddate'] = enddate;
return data;
},
"complete": function (response) {
}
},
"columnDefs": table,
"language": {
"emptyTable": "No data available in table",
"zeroRecords": "No data available in table",
"info": "Showing <b>_START_</b> to <b>_END_ of _TOTAL_</b> entries",
"paginate": {
"first": "First",
"last": "Last",
"next": "Next",
"previous": "Previous"
},
search: "_INPUT_",
searchPlaceholder: "Search..."
},
dom: 'Bfrtip',
buttons: [
'csv', 'excel', 'pdf'
]
});