您需要检查要选择的选项，然后打印选定的标签：

$civil_status = $row[8]; //value from selecting the database
<tr> 
<td>Civil Status:</td> 
<td><select name="civil_status" >
<option value="single" <?php $civil_status=="single" ? print "selected" : ""; ?> >Single</option>
<option value="married" <?php $civil_status=="married" ? print "selected" : ""; ?> >Married</option>
</select></td>
</tr>

您需要selected="selected"在选项标签中设置。像这样尝试

$civil_status = $row[8]; //value from selecting the database
    <tr> 
    <td>Civil Status:</td> 
    <td><select name="civil_status">
    <option value="single" <?php if($civil_status == 'Single') echo 'selected="selected"';?>>Single</option>
    <option value="married" <?php if($civil_status == 'Married') echo 'selected="selected"';?>>Married</option>
    </select></td>
    </tr>

您可以通过快速而肮脏的方式来做到这一点：

<tr>
    <td>Civil Status:</td> 
    <td>
        <select name="civil_status">
            <option value="single"<?php print($civil_status == "single" ? ' selected="selected"' : ""); ?>>Single</option>
            <option value="married"<?php print($civil_status == "married" ? ' selected="selected"' : ""); ?>>Married</option>
        </select>
    </td>
</tr>

或者您可以编写一个辅助函数来生成整个<option>集合：

function select_options($options, $selected)
{
    $result = "";
    foreach($options as $value => $label)
    {
         $result .= '<option value="' . 
             htmlentities($value, ENT_QUOTES, "UTF-8") . '"' . 
             ($selected == $value ? ' selected="selected"' : "") . '>' .
             htmlentities($label, ENT_QUOTES, "UTF-8") . '</option>';
    }
    return $result;
}

select_options有两个参数。第一个是关联数组 ( key => value, ...)，其中数组键是value各个<option>标签的参数值，数组值包含要为每个键显示的标签。

第二个参数指定value要在选择框中选择的项目。

然后该函数遍历数组并为每个项目提取value和。label然后它将相应的<option>标签附加到结果字符串中。它还在参数上调用htmlentities以避免跨站点脚本漏洞。

然后是踢球者：如果它在选择框 ( ) 中看到应该选择的项目，它会自动将参数$selected == $value附加到标签并因此选择该元素。selected="selected"<option>

要使用该功能，请执行以下操作：

<tr>
    <td>Civil Status:</td> 
    <td>
        <select name="civil_status">
            <?php
                  print(select_options(array(
                       "single" => "Single",
                       "married" => "Married"
                  ), $civil_status));
            ?>
        </select>
    </td>
</tr>

在您需要创建选择菜单的任何地方都更加清洁和可重复使用。

你可以试试这个，

       <?php   
          $civil_status = $row[8]; //$civil_status ='married';
          $civil_statuses = array('single', 'married'); 
        ?>

        <select name="civil_status">
            <?php foreach($civil_statuses as $status){ ?>
                <option value="<?php echo $status;?>" <?php  echo if($civil_status==$status){ echo 'selected';} ?> ><?php echo ucfirst($status);?></option>
            <?php }?>
        </select>