Question

以下是我要做的事情： - 我需要一个函数，当作为参数传递时，ID（对于一类事物）将提供所有子类别和子子类别以及sub-sub-sub..etc。 - 我正在考虑使用递归函数，因为我不知道它们的子子类别的子类别的数量等等所以这就是我到目前为止所做的事情

function categoryChild($id) {

    $s = "SELECT * FROM PLD_CATEGORY WHERE PARENT_ID = $id";
    $r = mysql_query($s);

    if(mysql_num_rows($r) > 0) {

        while($row = mysql_fetch_array($r))
            echo $row['ID'].",".categoryChild($row['ID']);
    }
    else {
        $row = mysql_fetch_array($r);
        return $row['ID'];
    }
}

如果我使用return而不是echo，我将得不到相同的结果。我需要一些帮助来解决这个问题或从头开始重写

Answer 1

我很难弄清楚你的功能。我想这会做你想要的。它获取ID $ id类别的所有子项，以及它们的子项（从而获得您想要的整个子类别，子子类别效果）。

function categoryChild($id) {
    $s = "SELECT ID FROM PLD_CATEGORY WHERE PARENT_ID = $id";
    $r = mysql_query($s);

    $children = array();

    if(mysql_num_rows($r) > 0) {
        # It has children, let's get them.
        while($row = mysql_fetch_array($r)) {
            # Add the child to the list of children, and get its subchildren
            $children[$row['ID']] = categoryChild($row['ID']);
        }
    }

    return $children;
}

此功能将返回：

$var = array(
        'categoryChild ID' => array(
                'subcategoryChild ID' => array(
                        'subcategoryChild child 1' => array(),
                        'subcategoryChild child 2' => array()
                )
        ),
        'anotherCategoryChild ID' => array() # This child has no children of its own
);

它基本上返回一个包含子ID的数组和一个包含其子ID的数组。我希望这有任何帮助。

Answer 2

database tree to multidimensional array

<?php
function getTree($rootid)
{
   $arr = array();

   $result = mysql_query("select * from PLD_CATEGORY where PARENT_ID='$rootid'");
   while ($row = mysql_fetch_array($result)) { 
     $arr[] = array(
       "Title" => $row["Title"],
       "Children" => getTree($row["id"])
     );
   }
   return $arr;
}
?>

Answer 3

由于这是由@Pawan Sharma提出的，我认为我也可以给出一些答案。

所有给定的解决方案都存在常见问题 - 它们为每个孩子执行SQL查询。例如，如果第二级有100个孩子，那么将完成100个查询，而实际上可以使用where parent_id in (<list_of_ids>)在单个查询中完成。

示例DB：

create table category (
    id          int auto_increment primary key,
    parent_id   int default null,
    title       tinytext,
    foreign key (parent_id) references category (id)
) engine = InnoDB;

insert into category (id, parent_id, title) values
    (1, null, '1'),
    (2, null, '2'),
    (3, null, '3'),
    (4, 1   , '1.1'),
    (5, 1   , '1.2'),
    (6, 1   , '1.3'),
    (7, 4   , '1.1.1'),
    (8, 4   , '1.1.2'),
    (9, 7   , '1.1.1.1');

这是我的解决方案：

/**
 * @param null|int|array $parentID
 */
function getTree($parentID) {
    $sql = "select id, parent_id, title from category where ";
    if ( is_null($parentID) ) {
        $sql .= "parent_id is null";
    }
    elseif ( is_array($parentID) ) {
        $parentID = implode(',', $parentID);
        $sql .= "parent_id in ({$parentID})";
    }
    else {
        $sql .= "parent_id = {$parentID}";
    }

    $tree = array();
    $idList = array();

    $res = mysql_query($sql);
    while ( $row = mysql_fetch_assoc($res) ) {
        $row['children'] = array();
        $tree[$row['id']] = $row;
        $idList[] = $row['id'];
    }
    mysql_free_result($res);

    if ( $idList ) {
        $children = getTree($idList);
        foreach ( $children as $child ) {
            $tree[$child['parent_id']]['children'][] = $child;
        }
    }
    return $tree;
}

使用提供的示例数据，当调用getTree(null)时（对于所有条目），它最多可执行5次查询：

select id, parent_id, title from category where parent_id is null
select id, parent_id, title from category where parent_id in (1,2,3)
select id, parent_id, title from category where parent_id in (4,5,6)
select id, parent_id, title from category where parent_id in (7,8)
select id, parent_id, title from category where parent_id in (9)

当调用getTree(4)时，会执行3个查询：

select id, parent_id, title from category where parent_id = 4
select id, parent_id, title from category where parent_id in (7,8)
select id, parent_id, title from category where parent_id in (9)

Answer 4

function categoryChild($id)
{
    $s = "SELECT category_id,name FROM proads_categories WHERE parent_id =".$id;    
    $r = mysql_query($s);
    $children = array();
    if(mysql_num_rows($r) > 0)
    {
        #It has children, let's get them.
        while($row = mysql_fetch_array($r))
        {          
            #Add the child to the list of children, and get its subchildren
            $children[$row['category_id']]['nam'] = $row['name'];
            $arr = categoryChild($row['category_id']);
            if(count($arr) > 0)
            {
                $children[$row['category_id']]['child'] = categoryChild($row['category_id']);
            } 
        }
    }
    return $children;
}

这很完美。如果您需要，请试试这个

Answer 5

function breadCrumb($id)
{
    $ar = array();
    $result = mysql_query("SELECT * FROM groups WHERE ParentID = '$id'");
    if(mysql_num_rows($result) > 0)
    {
        while($row = mysql_fetch_object($result))
        {
            $ar[] = $row->DBGroupID;
            $r = mysql_query("SELECT * FROM groups WHERE ParentID = '".$row->GroupID."'");
            if(mysql_num_rows($r) > 0)
                $ar = array_merge($ar, breadCrumb($row->GroupID, 1));
        }
    }
    return $ar;
}

Answer 6

<?php    
require('db/dbconnect.php');   

$user_id='triD-100';   
 $sql="select * from ajent_joining where sponser_id='".$user_id."'";   
 $qR=mysql_query($sql);   
 while($rowD=mysql_fetch_assoc($qR)){    
  echo $childId=$rowD["user_id"]; 
    echo "<br/>";  
  categoryChild($childId);    
   }   

  function categoryChild($childId) {   

    $s = "select user_id from ajent_joining where sponser_id='".$childId."'";
    $r = mysql_query($s);
    if(mysql_num_rows($r) > 0) {

       while($row = mysql_fetch_array($r)) {

          echo $childId=$row["user_id"];
          echo "<br/>";   
           categoryChild($childId);
    }
}

}


?>

Answer 7

使用Prestashop功能：

public function getRecursiveChildren() {

    $subCategories = $this->recurseLiteCategTree();
    //print_r($subCategories);


    $my_tab = array();

    foreach ($subCategories['children'] as $subc) {
        $my_tab[]   = $subc['id'];
        foreach ($subc['children'] as $subc2) {
            $my_tab[]   = $subc2['id'];
            foreach ($subc2['children'] as $subc3) {
                $my_tab[]   = $subc3['id'];
                foreach ($subc3['children'] as $subc4) {
                    $my_tab[]   = $subc4['id'];
                }
            }
        }
    }
    $my_tab [] = $this->id; 

    return $my_tab;
}

这可以通过使用递归来改善，但今天没有时间：'（

获取所有子类别的递归函数

7 个答案: