选择其他名称或大小时，我尝试更新披萨ID。这些是从数据库中列出的可用选项，因此毫无问题，但是当按下“提交”按钮时，我收到错误消息“ where子句中的“未知名称”的“披萨名称””，该名称始终是最后一个选项名称。
因此，这些是列出的选项：
<td class="lekerdezes_oszlop">
<?php
$sql_select_2 = "SELECT DISTINCT(etel_nev) FROM etelek ORDER BY etel_id";
$result2 = $conn->query($sql_select_2);
echo "<select name=etel_nev>";
echo "<option value=$row[etel_nev]>- $row[etel_nev] -</option>";
foreach ($conn->query($sql_select_2) as $row2){
echo "<option value=$row2[etel_nev]>$row2[etel_nev]</option>";
}
echo "</select>";
?>
</td>
<td class="lekerdezes_oszlop">
<?php
$sql_select_3 = "SELECT DISTINCT(etel_meret) FROM etelek ORDER BY etel_id";
$result3 = $conn->query($sql_select_3);
echo "<select name=etel_meret>";
echo "<option value=$row[etel_meret]>- $row[etel_meret] -</option>";
foreach ($conn->query($sql_select_3) as $row3){
echo "<option value=$row3[etel_meret]>$row3[etel_meret]</option>";
}
echo "</select>";
?>
</td>
和更新本身：
if (isset($_POST['rendeles_id'])) {
$sql_update_2 = "UPDATE rendeles
SET etel_id = (SELECT etel_id FROM etelek WHERE etel_nev = $row2[etel_nev] AND etel_meret = $row3[etel_meret])
WHERE rendeles_id = '" . $_POST['rendeles_id'] . "'";
if ($conn->query($sql_update_2) === TRUE) {
echo "<p class='siker_uzenet'>Sikeres adatfrissítés</p>";
}
else {
echo "<p class='hiba_uzenet'>Hiba az adatok frissítésében: </p>" . $conn->error;
}
}