complete code`

<?php

$servername = "localhost";
$username = "root";
$password = "Outthinking123@";
$dbname = "designer6";

include 'home.php';
$user_home = new USER();


echo "<pre>";print_r($_POST);

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}


$stmt = $user_home->runQuery("SELECT * FROM tbl_users");
$stmt->execute(array(":uid" => $_SESSION['userSession']));
$row = $stmt->fetch(PDO::FETCH_ASSOC);
$stmt->execute();
$queryCondition='';
 // echo 'SELECT * FROM order_details '.$queryCondition;
?>

<?php

function getDesignerCollection()
{
    $user_home = new USER();
    require_once '../../app/Mage.php';
    Mage::app();
    $stmts = $user_home->runQuery("SELECT * FROM tbl_users WHERE userID=:uid");
    $stmts->execute(array(":uid"=>$_SESSION['userSession']));
    $rows = $stmts->fetch(PDO::FETCH_ASSOC);

    $accountType=$rows['type'];
    if($accountType=="admin"){

        $order = Mage::getModel('sales/order')->getCollection()->addAttributeToFilter('designer_id',array('nin'=>'0'));

    }
    else
    {
        $order = Mage::getModel('sales/order')->getCollection()->addAttributeToFilter('designer_id',array('like' => '%'.$_SESSION['userSession'].'%'));
    }

    $i=0;
    foreach ($order as $orderData)
    {

        $orderitems=$orderData['dproduct_id'];
        $orderitemsarray=explode(",",$orderitems);
        $k=0;

        $oDate = new DateTime($orderData['created_at']);
        $sDate = $oDate->format("Y-m-d");
        while($k < count($orderitemsarray))
        {
            if($orderitemsarray[$k]!='0')
            {

                $stmtorders = $user_home->runQuery("SELECT * FROM order_details WHERE designerorder_id=:designerorder_id");
                $stmtorders->execute(array(":designerorder_id"=>$orderData['entity_id']));

                $roworders = $stmtorders->fetch(PDO::FETCH_ASSOC);

                if($roworders['designerorder_id']==''){$dorderStatus="Unpaid";}else{$dorderStatus=$roworders['paid_status'];}

                $productdetail=Mage::getModel('catalog/product')->load($orderitemsarray[$k]);

                $responce[]=array($orderData->getIncrementId(),$orderData->getIncrementId(),$orderitemsarray[$k],$productdetail->getName(),$designerName,$orderData['status'],$orderData['grand_total'],$orderData['customer_email'],$orderData['shipping_description'],$dorderStatus,$sDate);

            }
            $k++; $i++;
        }

    }		echo json_encode($responce);

}

/* Date */
$reg_user='';

$post_at = "";
$post_at_to_date = "";
$queryCondition = "";

	if( !empty( $_POST[ 'post_at' ] ) )
{
    $post_at        = date( 'Y-m-d', strtotime( $_POST[ 'post_at' ] ) );
    $post_at_todate = date( 'Y-m-d' );
    if( !empty( $_POST[ 'post_at_to_date' ] ) )
    {
        $post_at_to_date = date( 'Y-m-d', strtotime( $_POST[ 'post_at_to_date' ] ) );
        $post_at_todate = $post_at_to_date;
    }
    $queryCondition .= "WHERE DATE( post_at ) >= '" . $post_at . "' AND DATE( post_at ) <= '" . $post_at_todate . "'";
}

$sqlquery = "SELECT * FROM order_details $queryCondition";
var_dump( $sqlquery );


    $result = $conn->query($sqlquery);

    if ($result->num_rows > 0) {
        echo $result->num_rows.'result found'."<br>";
        while($row = $result->fetch_assoc()) {
            echo "id: " . $row["id"]. " - date: " . $row["post_at"];
            echo "<br>";
        }
    } else {
        echo "0 results found <br>";
    }
$conn->close();
?>

<head>

    <script src="http://code.jquery.com/ui/1.10.3/jquery-ui.js"></script>
    <script src= "http://ajax.googleapis.com/ajax/libs/jqueryui/1.10.3/jquery-ui.js"></script>

    <link rel="stylesheet" href="assets/css/jquery-ui.css">
    <script src="assets/js/jquery-1.10.2.js"></script>
    <script src="assets/js/jquery-ui.js"></script>
    <script src="assets/js/jquery-ui.js"></script>

    <script>
jQuery.datepicker.setDefaults({
showOn: "button",
buttonImage: "datepicker.png",
buttonText: "Date Picker",
buttonImageOnly: true,
dateFormat: 'yy-mm-dd'
});
$(function() {
$("#post_at").datepicker();
$("#post_at_to_date").datepicker();
});
</script>

    <script type="text/javascript" language="javascript" src="http://sbdev2.kidsdial.com:81/php/site6/bootstrap/js/outthinking/gt_msg_en.js"></script>
    <script type="text/javascript" language="javascript" src="http://sbdev2.kidsdial.com:81/php/site6/bootstrap/js/outthinking/gt_grid_all.js"></script>


    <link rel="stylesheet" type="text/css" href="http://sbdev2.kidsdial.com:81/php/site6/bootstrap/css/outthinking/css/skinstyle.css"/>
    <link rel="stylesheet" type="text/css" href="http://sbdev2.kidsdial.com:81/php/site6/bootstrap/css/outthinking/css/gt_grid.css"/>

</head>

<div>
    <div class="delete_grid" >
        Search:
        <select id="f_value2">
            <option value="entity_id">Order Id</option>
            <option value="designer_id">Designer Id</option>
        </select>
        <input type="text" onkeyup="doFilter()" value="" id="f_value1" >


        <br/>

        <form name="frmSearch" method="post" action="">
<input type="text" placeholder="From Date" id="post_at" value="" name="post_at" />
<input type="text" placeholder="To Date" id="post_at_to_date" value="" name="post_at_to_date" />
<input type="submit" name="search" value="search" />
</form>
    </div>
</div>
<div id="myGrid"></div>

<script type="text/javascript">

    var __TEST_DATA__=eval('<?php echo getDesignerCollection();?>');
    var grid_demo_id = "myGrid" ;
    var dsOption= {
        fields :[
            {name : 'entity_id'  },
            {name : 'entity_id'  },
            {name : 'product_id'  },
            {name : 'product_name'},
            {name : 'designer_id'  },
            {name : 'status'  },
            {name : 'grand_total'  },
            {name : 'customer_email'  },
            {name : 'shipping_description'  },
            {name : 'paid_status'  },
            {name : 'created_at'},
        ],
        recordType : 'array',
        data : __TEST_DATA__
    }


    function my_renderId(value ,record,columnObj,grid,colNo,rowNo)
    {
        var no= record[columnObj.fieldIndex];

        return "<input type='checkbox' value='"+record[0]+"' name='userID'/>";
    }

    var colsOption = [
        {id: 'entity_id' , header: "Order Id" , width :"15",renderer : my_renderId},
        {id: 'entity_id' , header: "Order Id" , width :"75"},

        {id: 'created_at' , header: "Order Date" , width :"120"}

    ];

    var gridOption={
        id : grid_demo_id,
        //height: "285",  //"100%", // 330,
        pageSize:20,
        pageSizeList : [5,10,15,20],
        container : 'myGrid',
        replaceContainer : true,
        dataset : dsOption ,
        columns : colsOption ,
        toolbarContent : 'nav goto | pagesize | filter state | sortable | search',
        onRowClick:function(value, record , cell, row,  colNO, rowNO,columnObj,grid){
        }
    };
    var mygrid=new Sigma.Grid(gridOption);
    Sigma.Util.onLoad( Sigma.Grid.render(mygrid) );

    function doFilter() {
        var filterInfo=[
            {
                fieldName : $('select[id=f_value2]').val(),
                logic : "startWith",
                value : Sigma.Util.getValue("f_value1")
            },
            {
                fieldName : Sigma.Util.getValue("f_fieldName12"),
                logic : "greatEqual",
                value : Sigma.Util.getValue("f_value12")
            }
        ]
        var grid=Sigma.$grid("myGrid");
        var rowNOs=grid.applyFilter(filterInfo);
    }
    function doUnfilter(){
        var grid=Sigma.$grid("myGrid1");
        var rowNOs=grid.unfilterGrid();

    }

    function massAction()
    {
        var e=document.getElementById("massaction");
        var strUser = e.options[e.selectedIndex].value;

        switch(strUser)
        {
            case "paid":
                retactiveVal=confirm("Are you sure want to Change the Paid status");
                if( retactiveVal == true )
                {
                    massdesignerpaidstatus();
                    return true;
                }else{
                    return false;
                }

                return false;
        }
    }

</script>