mysql&；php select*查询不工作

我在数据库中有一个名为sales的表。每行在federal列中都有一个值。 所以我想在这段代码中收集一个数组中的所有联邦成员，但它不起作用，我不知道为什么。。。请帮忙！谢谢

  <?php
              $db = mysqli_connect("server", "usr", "pw", "db");

              $FederalRes = $db->query("SELECT * FROM `sales` WHERE `state` = 'Österreich'"); //gets every row with the state = 'Österreich'

              $federals = array(); // empty array to collect federals

              while ($row = $FederalRes->fetch_object()) {
                if (!in_array($row->federal, $federals)) { // check if federal is already in array
                  array_push($federals, $row->federal); // adds federal to array
                }
              }

              sort($federals); // sorts the array alphabetically

              foreach ($federals as $key => $value): ?>
                <li><?php echo $value ?></li>
              <?php endforeach; ?>

---

您尝试使用
LIKE
语句，而不是
=

请使用以下代码进行尝试：

<?php
  $db = mysqli_connect("server", "usr", "pw", "db");

  $FederalRes = $db->query("SELECT * FROM `sales` WHERE `state` LIKE 'Österreich'"); //gets every row with the state = 'Österreich'

  $federals = array(); // empty array to collect federals

  while ($row = $FederalRes->fetch_object()) {
    if (!in_array($row->federal, $federals)) { // check if federal is already in array
      array_push($federals, $row->federal); // adds federal to array
    }
  }

  sort($federals); // sorts the array alphabetically

  foreach ($federals as $key => $value): ?>
    <li><?php echo $value ?></li>
  <?php endforeach; ?>

连接工作正常吗？你和db有联系吗？怎么了？请提供更多信息。。在li元素中忘记了“echo”什么不起作用？您可能希望在foreach循环中使用
$federals
而不是
$variable
。连接工作正常，没有错误。。仅0行作为查询的回应。非常感谢！我不知道为什么，但它奏效了：）
<?php
try{
$conn = new PDO('mysql:host=localhost;dbname=test;charset=utf8', 'root',     '');
}

catch(Exception $e){
die('Erreur : '.$e->getMessage());
}

$answer= $conn->query("SELECT * FROM sales WHERE state LIKE 'Österreich' ORDER BY state ASC"); //sort it alphabetically here ;)


while ($data = $answer->fetch()){
    echo $data['federal'] . '<br />';
}
$reponse->closeCursor();

?>