Question

如何使用php中的while循环从以下下拉代码中选择特定项？

我可以填充下拉列表，但无法从下拉列表中选择特定项目。如果可以的话请帮忙。感谢。

<div class="form-group">
    <select name="submit" for="no_id">
    <?php 
        $query = "SELECT * FROM crap";
        $select_dropdown = mysqli_query($conn, $query);
        #function confirm stores in functions.php
        confirm($select_dropdown);
        while($row=mysqli_fetch_assoc($select_dropdown)){
            $keyas_id= $row['keyas_id'];
            $valueas_title =$row['valueas_title'];
            echo "<option value=$keyas_id>  $valueas_title </option>";
        }
    ?>
    </select>
</div>

Answer 1

$selectedId = 'Your selected ID';
$isSelected = '';

if ( $keyas_id === $selectedId) {
    $isSelected = "selected='selected'";
}
echo "<option value=$keyas_id $isSelected>  $valueas_title </option>";

Answer 2

您可以在选项中添加if条件，以便比较keyas_id是否等于selected_id，如果它相等，那么您可以选择以下内容：

<div class="form-group">
<select name="submit" for="no_id">
<?php 
    $query = "SELECT * FROM crap";
    $select_dropdown = mysqli_query($conn, $query);
    #function confirm stores in functions.php
    confirm($select_dropdown);
    $selectedId = 'Your selected ID';
    while($row=mysqli_fetch_assoc($select_dropdown)){
        $keyas_id= $row['keyas_id'];
        $valueas_title =$row['valueas_title'];
        echo "<option if($keyas_id==$selectedId) { selected='selected' } value=$keyas_id>  $valueas_title </option>";
    }
?>
</select>
</div>

如何使用Php Mysql中的while循环从下拉菜单中选择一个项目

2 个答案: