You can initiate new row adding from the toolbar ("+" button) or from an external control. In this example, we are using the toolbar navigator=true

Actually you should only set the table to where we should add a data. All other things are handled by the connector. It is important to note that the data binding is high secured. The grid determines automatically the field types and bind the appropriate data.
<?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>
  </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 CustomerID, CompanyName, Phone, PostalCode, City FROM customers';
// Set the table to where we add the data
$grid->table = 'customers';
// We tell that the primary key is not serial, which should be inserted by the user
$grid->serialKey = false;
// Set output 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 some grid options
$grid->setGridOptions(array(
    "rowNum"=>10,
    "rowList"=>array(10,20,30),
    "sortname"=>"CustomerID"
));
// The primary key should be entered
$grid->setColProperty('CustomerID', array("label"=>"Customer Name","editrules"=>array("required"=>true)));
// Enable navigator
$grid->navigator = true;
// Enable only adding
$grid->setNavOptions('navigator', array("excel"=>false,"add"=>true,"edit"=>false,"del"=>false,"view"=>false, "search"=>false));
// Close the dialog after the record is added
$grid->setNavOptions('add',array("closeAfterAdd"=>true,"reloadAfterSubmit"=>true, "width"=>350));
// Enjoy
$grid->renderGrid('#grid','#pager',true, null, null, true,true);
$conn = null;
?>