首页 > 解决方案 > 在 PHP 中使用 PDO 动态构建多级菜单

问题描述

我的数据库中有这些数据:

id  nameOfPerson    parent
3   John             NULL
4   Michel            3
5   Husam             4
6   Khalaf            5
7   Mark              5
----------------------------

我想像这样在列表中显示它

但在我的代码中,他只是显示

我想如何根据上面列表中的父级显示所有数据?

这是我的功能有什么问题?

  public function familyTree(){
    $query = "SELECT id, nameOfPerson, parent FROM person WHERE parent is null";
    $statment = $this->db->prepare($query);
    $statment->execute();
    echo '<ul id ="family">';
    while($family = $statment->fetch(PDO::FETCH_OBJ)){
        echo '<li>'. $family->nameOfPerson;
        $query1 = "SELECT id, nameOfPerson, parent FROM person WHERE parent = :id";
        $statment1 = $this->db->prepare($query1);
       $statment1->bindValue('id', $family->id);
        $statment1->execute();
        if($statment1->rowCount() > 0){
        echo '<ul>';
        while($family2 = $statment1->fetch(PDO::FETCH_OBJ)){
            echo '<li>' . $family2->nameOfPerson . '</li>';
        }
            echo '</ul>';
        }
            echo '</li>';
    }
            echo '</ul>';      

}

标签: phpmysqlpdohierarchy

解决方案


假设

  • 每个孩子只有1父母。

代码

  • 首先,我从数据库表中检索所有数据,因为为每个父级单独检索数据会增加数据库调用并影响响应时间,效率不高。

  • 建立一个由父母和孩子组成的关联数组,其中每个父母都有each child-nameOfPerson和2 个细节id

  • 以递归的方式迭代这个数组并继续为每个孩子构建列表并最终返回它们。

有关表行,请参阅SQL Fiddle

<?php

$pdo = new PDO("mysql:dbname=newdummy;host=localhost","root","");

$query = $pdo->query("Select * from hierarchy");

$family_tree = [];
$root_parent = -1;
$root_parent_name = "";

function makeTree($query,&$family_tree,&$root_parent,&$root_parent_name){
   while($row = $query->fetch(PDO::FETCH_ASSOC)){
      if(is_null($row['parent'])){
          $root_parent = $row['id'];
          $root_parent_name = $row['nameOfPerson'];
      }else{
          if(!isset($family_tree[$row['parent']])){
            $family_tree[$row['parent']] = [];
          }          
          $family_tree[$row['parent']][] = array($row['nameOfPerson'],$row['id']);
      }    
   }
}

function buildList($family_tree,$parent){
  $list = "<ul>";

  foreach($family_tree[$parent] as $each_child){
     $list .= "<li>" . $each_child[0];
     if(isset($family_tree[$each_child[1]])){
        $list .= buildList($family_tree,$each_child[1]);
     }
     $list .= "</li>";
  }

  $list .= "</ul>";

  return $list;
}


makeTree($query,$family_tree,$root_parent,$root_parent_name);


echo "<ul>";
echo "<li>$root_parent_name";
echo buildList($family_tree,$root_parent);
echo "</li>";
echo "</ul>";

输出

<ul>
    <li>John
        <ul>
            <li>Michel
                <ul>
                    <li>
                        Husam
                            <ul>
                                <li>khalaf</li>
                                <li>Mark</li>
                            </ul>
                    </li>
                </ul>
            </li>
            <li>Tross</li>
            <li>David</li>
        </ul>
    </li>
</ul>

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