我创建一个这样的下拉列表:
<header>
<h3 align="center"> Highway State </h3>
</header>
<section>
<article>
<hgroup>
</hgroup>
<p align="center">
<form style="text-align:center" method="post" action="">
<select name="dropdown1">
<?php echo query1(); ?>
</select>
<input type="submit" value="Submit" />
</form>
</p>
</article>
其中 query1() 是
function query1()
{
$myHTMLData = '';
$c=connect();
$myData=mysqli_query($c, "SELECT DISTINCT highway_state FROM highways_highway ORDER BY highway_state");
while($record = mysqli_fetch_array($myData))
{
$myHTMLData .= '<option value="' . $record['highway_state'] . '">' . $record['highway_state'] . '</option>' ;
}
return $myHTMLData;
}
所以我正在做的是用状态填充下拉菜单。
我现在的问题是如何执行 SELECT ID, exit_name FROM Highways_exit WHERE Highway_ID = (SELECT ID FROM Highways_highway WHERE Highway_state = * dropdown1 *之类的 sql 查询
* dropdown1 *是我希望查询基于 dropdown1 中的选择的位置。我该怎么做呢?
另外:当用户点击提交按钮时,如何在网页上显示此查询?
我对解决方案的尝试(用 index.php 编写)
<header>
<h3 align="center">Exit Name</h3>
</header>
<section>
<table border='1' align="center">
<tr>
<th>Exit Name</th>
<th>Exit ID</th>
</tr>
<?php
$c=connect();
$hstate = $_POST['dropdown1'];
$hname = $_POST['dropdown2'];
$hdir = $_POST['dropdown2pt5'];
$result=mysqli_query($c, "SELECT exit_name, id FROM highways_exit WHERE highway_ID = (SELECT id FROM highways_highway WHERE highway_state = ('" . $hstate . "') AND highway_name = ('" . $hname . "') AND highway_dir = ('" . $hdir . "')) ");
while($row = mysqli_fetch_array($result))
{
$arrexit = $row['exit_name'];
$arrid = $row['id'];
echo "<tr><td>$arrexit</td><td>$arrid</td></tr>";
}
?>
</table>
</section>
<footer>
<f1 align="center"></f1>
</footer>
这对使用菜单项是否正确?这个和菜单对象都在 index.php 上,有没有办法让它工作,以便它可以接收菜单项并在刷新/提交时生成这个表?