WPdb无法在自定义插件中工作

我试图在插件文件中使用wpdb，但由于某些原因，我没有收到错误，只是没有结果。

我只是想从表格中获得一些信息，并将其显示给最终用户，任何关于为什么它不起作用的想法

 function show_forminfo(){
     global $wpdb;
     $sql =  "SELECT * FROM 4hSIc_pods_player_ranking WHERE player_id='".$playerId."'";
     $clientRow = $wpdb->get_row( $wpdb->prepare($sql));
    echo $clientRow->points_to_redeem;
        echo "<div id='infopoints' class='modal fade' tabindex='-1' role='dialog' aria-labelledby='myModalLabel' aria-hidden='true'>";
        echo "<div class='modal-dialog'>";
        echo "<div class='modal-content'>";
        echo "<div class='modal-header'>";
        echo "<button type='button' class='close' data-dismiss='modal' aria-hidden='true'>×</button>";
        echo "<h4 class='modal-title'>Redeem Points</h4>";
        echo "</div>";
        echo "<form class='form-horizontal'  class='contact' name='redemmpointsForm' id='redemmpointsForm' >";
        echo " <div class='form-group'>";
        echo "<h3>You have points pending:<br />";
        echo "".$clientRow->points_to_redeem;
        echo "<input type='hidden' name='playerid' value='<?php echo $playerId;;?>' />";
        echo "     </div>";
        echo "    <div class='form-group'>";
        echo "            <div class='col-md-6'>";
        echo "     <a href='#' class='btn btn-info' data-dismiss='modal'>Close</a>";
        echo "         </div>";
        echo "      </div>";
        echo "</form>";
        echo "      </div>";
        echo "      </div>";
        echo "      </div>";
    }