Sorting is enabled by default for all jqGrid columns. To sort a column, just click on the header of the respective column.

The default sorting logic of the grid in almost all cases is good enough -- depending on the type of the column (date, int, float, double, etc) it sorts the column while switching ascending and descending orders.

You can choose the initial sorted column (column name) and the initial sort direction (asc, desc) when the grid first loads. This can be achieved by using the sortname collection and sortorder properties.

$grid->setGridOptions(array("sortname"=>"OrderID","sortorder"=>"desc"));
<?php 
require_once '../../../../php/demo/tabs.php';
?>
<!DOCTYPE html>
<html>
  <head>
    <title>jqGrid PHP Demo</title>
    <link rel="stylesheet" type="text/css" media="screen" href="../../../../css/jquery-ui.css" />
    <link rel="stylesheet" type="text/css" media="screen" href="../../../../css/trirand/ui.jqgrid.css" />
    <link rel="stylesheet" type="text/css" media="screen" href="../../../../css/ui.multiselect.css" />
    <style type="text">
        html, body {
        margin: 0;            /* Remove body margin/padding */
        padding: 0;
        overflow: hidden;    /* Remove scroll bars on browser window */
        font-size: 75%;
        }
        
    </style>
    <script src="../../../../js/jquery.min.js" type="text/javascript"></script>
    <script src="../../../../js/trirand/i18n/grid.locale-en.js" type="text/javascript"></script>
         <script src="../../../../js/trirand/jquery.jqGrid.min.js" type="text/javascript"></script> <script type="text/javascript">         
    $.jgrid.no_legacy_api = true;
    $.jgrid.useJSON = true;
    $.jgrid.defaults.width = "700";
    </script>
    <script src="../../../../js/jquery-ui.min.js" type="text/javascript"></script>
    <script src="../../../../js/ui.multiselect.js" type="text/javascript"></script>
     
  </head>
  <body>
      <div>
          <?php include ("grid.php");?>
      </div>
      <br/>
      <?php tabs(array("grid.php"));?>
   </body>
</html>
grid.php.
<?php
require_once '../../jq-config.php';
// include the jqGrid Class
require_once ABSPATH."php/PHPSuito/jqGrid.php";
// include the driver class
require_once ABSPATH."php/PHPSuito/DBdrivers/jqGridPdo.php";
// Connection to the server
$conn = new PDO(DB_DSN,DB_USER,DB_PASSWORD);
// Tell the db that we use utf-8
$conn->query("SET NAMES utf8");

// Create the jqGrid instance
$grid = new jqGridRender($conn);
// Write the SQL Query
$grid->SelectCommand = 'SELECT OrderID, OrderDate, CustomerID, Freight, ShipName FROM orders';
// set the ouput format to json
$grid->dataType = 'json';
// Let the grid create the model
$grid->setColModel();
// Set the url from where we obtain the data
$grid->setUrl('grid.php');
// Set the initial sorting column using the sortname oprion
$grid->setGridOptions(array("sortname"=>"OrderID","sortorder"=>"desc","rowNum"=>10,"rowList"=>array(10,20,30)));
// Change some property of the field(s)
$grid->setColProperty("OrderDate", array(
    "formatter"=>"date",
    "formatoptions"=>array("srcformat"=>"Y-m-d H:i:s","newformat"=>"m/d/Y")
    )
);
// Enjoy
$grid->renderGrid('#grid','#pager',true, null, null, true,true);