bootstrap-table fliter-control 下拉框数据重复

Question

<table id="factorytable" data-pagination="true" data-page-number="1"            data-page-size="13" data-search="true" data-filter-control="true" data-filter-show-clear="true"            data-toggle="table"            class="table table-hover">         <thead>         <tr>             <th style="text-align: center; " data-field="id" data-filter-control="select">                 序号             </th>             <th style="text-align: center; " data-field="factoryname">                 厂家名称             </th>         </tr>         </thead>         <tbody>         <tr data-index="0">             <td style="text-align: center; ">1</td>             <td style="text-align: center; "></td>         </tr>         <tr data-index="1">             <td style="text-align: center; ">2</td>             <td style="text-align: center; "></td>         </tr>         </tbody>     </table>