Mysql代码不在wampserver高版本中

Question

我的代码在wampserver较低的服务器上运行良好，但是当我尝试转移到更高版本时。 wampserver 3.0，即使我使用mysqli面向对象类型也显示错误。但是当我通过mysql删除组。它已经有效但我需要使用group by。

注意：尝试获取非对象的属性

 <?php
        $sql = "SELECT * from barcode  where status='COMPLETE'  group by refnumber ORDER BY refnumber  ASC    ";
        $result = $conn->query($sql);

        if ($result->num_rows == 0)
        {
        echo " No Transactions for Today";
        }
        if ($result->num_rows > 0) {

        echo " 
        <table class='table table-bordered table-hover table-condensed '>
        <tr class='success'> <th>Ref.Number</th><th> Model </th> <th>Date Received</th><th>Time</th> <th>Status</th> <th>Received By</th>  <th>Action</th> 
        </tr>";

        $current_cat = null;

        while($row = $result->fetch_assoc()) {

        if ($row["refnumber"] != $current_cat) { 
        $current_cat = $row["refnumber"];   
        $current_cat2 = $row["datereceived"];
        $current_cat3 = $row["status"];
        $current_cat4 = $row["datetime"];
        $current_cat5 = $row["user"];
        echo "<tr><td>";

        echo"
        {$current_cat}</td> <td><a href='viewitem.php?Rid=".$row['refnumber']."')>View</a></td> <td>{$current_cat2}</td> <td>{$current_cat4}</td><td>{$current_cat3}</td><td>{$current_cat5}</td>

        ";?>
        <td>
        <a href="print_pdf.php?Rid=<?=$row['refnumber']?>" target="_TOP">Print</a>

        </td>

        <?php
        }}}
        ";?>
        </table>