ThinkPHP表格动态rowspan

需求

记录集参考文章
MYSQL|count()函数使用条件分别统计
代码

<table lay-filter="ftTb" class="layui-table">
    <thead>
        <tr>
            <th>No</th>
            <th>类别</th>
            <th>类别明细</th>
            <th>提交数</th>
            <th>处理数</th>
            <th>合格数</th>
            <th>不合格数</th>
        </tr>
    </thead>
    <tbody>
        <?php
            $prev=0;
        ?>
        <volist name="list" id="vo">

            <tr>
                <?php
                    if($vo[class1_id]!=$prev){
                        $sql="
                            select count(*)
                            from `class2`
                            where class2_class1_id=$vo[class1_id]
                        ";
                        $rowspan=current(M()->query($sql)[0]);
                ?>
                    <td rowspan="{$rowspan}">{$vo[class1_id]}</td>
                    <td rowspan="{$rowspan}">{$vo[class1_name]}</td>
                <?php
                    }
                ?>
                <td>{$vo[class2_name]}</td>
                <td>{$vo[count_all]}</td>
                <td>{$vo[count_done]}</td>
                <td>{$vo[count1]}</td>
                <td>{$vo[count2]}</td>
            </tr>
            <?php $prev=$vo[class1_id];?>
        </volist>
    </tbody>
</table>