我的选择菜单每次显示每个端口(伦敦，利物浦，都柏林）对于每个记录，我只想要每个端口一次 - My select menu shows each port (London, Liverpool, Dublin) each time for each record, I only want each port once

My select menu shows each port (London, Liverpool, Dublin) each time for each record, I only want each port once

这是查询，它返回对我的游轮和票价表的搜索：

SELECT *, MIN(fares.offered) FROM cruises,fares 
WHERE cruises.departs > CURDATE() AND (cruises.destination LIKE %s OR 
  cruises.second_destination LIKE %s) AND 
  EXTRACT(YEAR_MONTH from cruises.departs) LIKE %s 
  AND cruises.fromport LIKE %s 
  AND cruises.ship LIKE %s AND cruises.live = 'Y' 
  AND fares.cruise_id = cruises.id 
GROUP BY fares.cruise_id ORDER BY cruises.departs, cruises.fromport"

我有一些跳转菜单，以便用户可以缩小搜索范围，例如上面的查询返回2012年7月的所有游轮，有一些，一些从伦敦出发，一些从利物浦出发。

我的港口选择菜单上填充了所有航班，如下所示

London
Liverpool
London
London
Liverpool

7月每次返回的航次记录一次。

我只想要

London
Liverpool

这是选择代码：

<select name="jumpMenu3" id="jumpMenu3" onchange="MM_jumpMenu('parent',this,0)">
    <option value="">Select a port</option>
    <?php
    $port = ''; 
    mysql_data_seek($cruises, 0);
    while ($row_cruises = mysql_fetch_assoc($cruises)) { 
        if ($row_cruises['fromport'] != $port) {
            $port = $row_cruises['fromport'];
    ?>
    <option value="index.php?subj=2&destination=<?php 
       echo urlencode($row_cruises['destination']);
    ?>&departs=<?php 
      echo date('Ym',strtotime($row_cruises['departs']));
    ?>&port=<?php 
      echo urlencode($port);?>"<?php 
    if ($_GET['port'] == $row_cruises['fromport']) {
      echo "selected='"selected'"";
    } 
    ?>><?php echo $port; ?></option>
    <?php } ;
    }
    if(mysql_num_rows($cruises) > 0) {
        mysql_data_seek($cruises, 0);
        $row_cruises = mysql_fetch_assoc($cruises);
    }
    ?>
    </select>

我想到了 GROUP BY，但我不能在港口的搜索查询中使用它，因为显然每个港口都有不止一个航班，也许我需要对月份选择选项进行单独的查询 - 或者我可以使用 php 分组吗？

最好的方法是另一个查询来检索端口名称，如下所示：

SELECT DISTINCT fromport FROM cruises WHERE cruises.departs > CURDATE()

您可以添加应适用的其他条件。

第二种方法可以在 PHP 中完成：

$ports = array(); 
mysql_data_seek($cruises, 0);
while ($row_cruises = mysql_fetch_assoc($cruises)) { 
    if (!in_array($row_cruises['fromport'], $ports)) {
        $ports[] = $row_cruises['fromport'];
?>
<option value="index.php?subj=2&destination=<?php echo urlencode($row_cruises['destination']);?>&departs=<?php echo date('Ym',strtotime($row_cruises['departs']));?>&port=<?php echo urlencode($row_cruises['fromport']);?>"<?php if ($_GET['port'] == $row_cruises['fromport']) {echo "selected='"selected'"";}?>><?php echo $row_cruises['fromport']; ?></option>
<?php
    }
}
if(mysql_num_rows($cruises) > 0) {
    mysql_data_seek($cruises, 0);
    $row_cruises = mysql_fetch_assoc($cruises);
}