PHP使用SQL數據填充下拉列表

Question

我想用數據庫中的值填充一個下拉列表。

<?php
require 'conn.php';

$filter=mysql_query("select distinct fuel_type from car");
while($row = mysql_fetch_array($filter)) {
$options ="<option>" . $row['fuel_type'] . "</option>";

$menu="<form id='filter' name='filter' method='post' action=''>
  <p><label>Filter</label></p>
    <select name='filter' id='filter'>
      " . $options . "
    </select>
</form>";

echo $menu;
}
?>

問題是我得到兩個列表，而不是一個包含值的列表。 請指教

Answer 1

echo $menu; 應該在循環之外。

Answer 2

您需要從循環中刪除$menu ：

<?php
require 'conn.php';

$options = '';
$filter=mysql_query("select distinct fuel_type from car");
while($row = mysql_fetch_array($filter)) {
    $options .="<option>" . $row['fuel_type'] . "</option>";
}

$menu="<form id='filter' name='filter' method='post' action=''>
  <p><label>Filter</label></p>
    <select name='filter' id='filter'>
      " . $options . "
    </select>
</form>";

echo $menu;

?>

Answer 3

<?php
require 'conn.php';

$filter=mysql_query("select distinct fuel_type from car");
$menu="
<form id='filter' name='filter' method='post' action=''>
  <p><label>Filter</label></p>
    <select name='filter' id='filter'>";

// Add options to the drop down
while($row = mysql_fetch_array($filter))
{
  $menu .="<option>" . $row['fuel_type'] . "</option>";
}

// Close menu form
$menu = "</select></form>";

// Output it
echo $menu;
?>