Php 如何在一个MySQL Select查询中做到这一点，我想丢失foreach循环和第二个Select查询？

下面的代码给出了我想要的结果，但它涉及2个数据库查询。我更愿意通过一个数据库查询来更高效地完成这项工作。是否有一种方法可以构造SELECT语句，通过一个数据库查询获得下面所需的结果

DB表：费率

费率结构：id、季节id、propID、费率

try {

      $conn = new PDO("mysql:host=$host;dbname=$dbname", $user, $pass);
      $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
      $conn->exec("SET CHARACTER SET utf8");

      $sql = "SELECT DISTINCT(seasonID), season.seasonDesc FROM `rates`
                        INNER JOIN season
                        ON rates.seasonID = season.id
                        WHERE propID = :propID";

      $sqlprep = $conn->prepare($sql);

      $ar_val = array(':propID'=>$propID);

      if($sqlprep->execute($ar_val)) {
          while($row = $sqlprep->fetch(PDO::FETCH_OBJ)){

            $seasonID[$row->seasonDesc] = $row->seasonID;
            //print_r($seasonID);

           }

         }
    } catch(PDOException $e) {
      echo $e->getMessage();
    }

    foreach($seasonID AS $key => $value){
        echo "<b>".$key."</b>";
    echo "<ul>";


                try {

                    $conn = new PDO("mysql:host=$host;dbname=$dbname", $user, $pass);  
                    $conn->exec("SET CHARACTER SET utf8");

                    $sql = "SELECT * FROM `rates`
                                WHERE seasonID = :seasonID
                                AND propID = 1
                                ORDER BY AccomType,rateType";

                    $sqlprep = $conn->prepare($sql); 

                    $ar_val = array(':seasonID'=>$value);

                    if($sqlprep->execute($ar_val)) {
                        while($row = $sqlprep->fetch(PDO::FETCH_OBJ)){

                            echo "<li>".$row->accomType."<br>";
                            echo " ".$row->rateType." - ";
                            echo " R".number_format($row->rate,'2','.',' ')." ".$row->rateUnit."</li>";


                        }
                    }

                }
                catch(PDOException $e) {
                    echo $e->getMessage();
                }
    echo "</ul>";
    } 

所需结果（foreach循环给我这个结果）：

    Season 1 Property 1 rate: 1
    Season 1 Property 2: rate 1
    Season 1 Property 3: rate 1
    Season 2 Property 1 rate: 1
    Season 2 Property 2: rate 1
    Season 2 Property 3: rate 1
    Season 3 Property 1 rate: 1
    Season 3 Property 2: rate 1
    Season 3 Property 3: rate 1

Season 1
    Property 1 rate: 1
    Property 2: rate 1
    Property 3: rate 1

Season 2
    Property 1 rate: 1
    Property 2: rate 1
    Property 3: rate 1

Season 3
    Property 1 rate: 1
    Property 2: rate 1
    Property 3: rate 1

---

首先：不要在循环中询问调用查询-这是非常无效的。只需一次查询，即可轻松下载所有数据：

$sql = "SELECT rates.*, season. seasonDesc FROM `rates`
       JOIN seasons ON rates.seasonID = season.id
       WHERE -- insert here proper where case
       ORDER BY AccomType,rateType"

现在，在循环遍历结果时，只需要一个小技巧：

$activeSeasonId = null;
while($row = $sqlprep->fetch(PDO::FETCH_OBJ)){
   if($activeSeasonId != $row->seasonID) {
        if(activeSeasonId != null) {
            //close previous <ul> here
        }
        // open new <ul> here

        $activeSeasonId = $row->seasonID;
   }
   // print your <li> here
}
//after everything close last <ul>

$activeSeasonId=null；
while（$row=$sqlprep->fetch（PDO:：fetch_OBJ））{
如果（$activeSeasonId！=$row->seasonID）{
如果（activeSeasonId！=null）{
//在此处关闭上一个

}
//在此处打开新

$activeSeasonId=$row->seasonID；
}
//在这里打印您的

}
//最后一次关闭后

---

诀窍是保存实际的季节ID，并在其更改时进行检查。然后你要做的就是打印新的seasonDesc并继续循环。

你的代码在哪里？我不能进行连接，因为这都是从一个表

季节。seasonDesc

是从另一个表来的，对吗？对不起，你是对的，忽略我的评论。我明白你说的很好，很简单，现在就试试。好的，它很好，有一个问题：我一开始就挂了。