问题:
我试图通过使用类删除类别的所有子级别.目前我只能删除两个子级别,而不是三个子级别.
数据库表:
CREATE TABLE betyg_category (
CID int(11) NOT NULL AUTO_INCREMENT,
Item varchar(100) NOT NULL,
Parent int(11) NOT NULL DEFAULT '0',
PRIMARY KEY (CID)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
PHP类:
<?PHP
class ItemTree
{
var $itemlist = array();
function ItemTree($query)
{
$result = MysqL_query($query) or die ('Database Error (' . MysqL_errno() . ') ' . MysqL_error());
while ($row = MysqL_fetch_assoc($result))
{
$this->itemlist[$row['CID']] = array(
'name' => $row['Name'],
'parent' => $row['Parent']
);
}
}
function get_tree($parent, $with_parent=0)
{
$item_tree = array();
if ($with_parent == 1 && $parent != 0)
{
$item_tree[$parent]['name'] = $this->itemlist[$parent]['name'];
$item_tree[$parent]['parent'] = $this->itemlist[$parent]['parent'];
$item_tree[$parent]['child'] = $this->get_tree($parent);
return $item_tree;
}
foreach ($this->itemlist as $key => $val)
{
if ($val['parent'] == $parent)
{
$item_tree[$key]['name'] = $val['name'];
$item_tree[$key]['parent'] = $val['parent'];
$item_tree[$key]['child'] = $this->get_tree($key);
}
}
return $item_tree;
}
function make_optionlist ($id, $class='', $delimiter='/')
{
$option_list = '';
$item_tree = $this->get_tree(0);
$options = $this->make_options($item_tree, '', $delimiter);
if (!is_array($id))
{
$id = array($id);
}
foreach($options as $row)
{
list($index, $text) = $row;
$selected = in_array($index, $id) ? ' selected="selected"' : '';
$option_list .= "<option value=\"$index\" class=\"$class\"$selected>$text</option>\n";
}
return $option_list;
}
function make_options ($item_tree, $before, $delimiter='/')
{
$before .= empty($before) ? '' : $delimiter;
$options = array();
foreach ($item_tree as $key => $val)
{
$options[] = array($key, '- '.$before.$val['name']);
if (!empty($val['child'])) {
$options = array_merge($options, $this->make_options($val['child'], $before.$val['name'], $delimiter));
}
}
return $options;
}
function get_navlinks ($navid, $tpl, $startlink='', $delimiter=' » ')
{
// $tpl typ: <a href="index.PHP?id={id}" class="navlink">{name}</a>
$search = array('{id}', '{name}');
$navlink = array();
while (isset($this->itemlist[$navid]))
{
$replace = array($navid, $this->itemlist[$navid]['name']);
$navlink[] = str_replace($search, $replace, $tpl);
$navid = $this->itemlist[$navid]['parent'];
}
if (!empty($startlink))
{
$navlink[] = str_replace($search, array(0, $startlink), $tpl);
}
$navlink = array_reverse($navlink);
return implode($delimiter, $navlink);
}
function show_tree ($parent=0, $tpl='%s', $ul_class='', $li_class='')
{
$item_tree = $this->get_tree($parent);
return $this->get_node($item_tree, $parent, $tpl, $ul_class, $li_class);
}
function get_node ($item_tree, $parent, $tpl, $ul_class, $li_class)
{
// $tpl typ: <a href="item.PHP?id={id}" class="treelink" style="color:blue">{name}</a>
$search = array('{id}', '{name}');
$output = "\n<ul class=\"$ul_class\">\n";
foreach ($item_tree as $id => $item)
{
$replace = array($id, $item['name']);
$output .= "<li class=\"$li_class\">".str_replace($search, $replace, $tpl);
$output .= !empty($item['child']) ? "<br />".$this->get_node ($item['child'], $id, $tpl, $ul_class, $li_class) : '';
$output .= "</li>\n";
}
return $output . "</ul>\n";
}
function get_id_in_node ($id)
{
$id_list = array($id);
if (isset($this->itemlist[$id]))
{
foreach ($this->itemlist as $key => $row)
{
if ($row['parent'] == $id)
{
if (!empty($row['child']))
{
$id_list = array_merge($id_list, get_id_in_node($key));
} else
{
$id_list[] = $key;
}
}
}
}
return $id_list;
}
function get_parent ($id)
{
return isset($this->itemlist[$id]) ? $this->itemlist[$id]['parent'] : false;
}
function get_item_name ($id)
{
return isset($this->itemlist[$id]) ? $this->itemlist[$id]['name'] : false;
}
}
?>
场景:
假设您在以下结构中具有以下结构:
>文学
> – 整合资源
> —-测试1
它将在数据库表中产生以下结果:
当我尝试删除这个子级别时,它会将最后一个子级别留在数据库中,同时它应该删除它.结果将是:
//Check if delete button is set
if (isset($_POST['submit-deletecategory']))
{
//Get $_POST variables for category id
$CategoryParent = intval($_POST['CategoryList']);
//Check if category is selected
if ($CategoryParent != "#")
{
//Get parent category and subsequent child categories
$query = "SELECT CID, Item AS Name, Parent FROM " . TB_CATEGORY . " ORDER BY Name";
$items = new ItemTree($query);
if ($items->get_item_name($_POST['CategoryList']) !== false)
{
//Build up erase list
$CategoryErase = $items->get_id_in_node($CategoryParent);
$CategoryEraseList = implode(", ", $CategoryErase);
}
else
{
$CategoryEraseList = 0;
}
//Remove categories from database
$query = "DELETE FROM " . TB_CATEGORY . " WHERE CID IN ($CategoryEraseList)";
$result = MysqL_query($query) or die ('Database Error (' . MysqL_errno() . ') ' . MysqL_error());
//Return a confirmation notice
header("Location: settings.PHP");
exit;
}
}
提前感谢您提供解决问题的任何指导.
解决方法:
这是一种方法:使用递归函数,它首先查找叶子项(树中最深的).您首先删除子项,然后删除父项.对于每个孩子,你先移除孩子的孩子等等……
deleteSub(1);
function deleteSub($cat_id) {
$request = "SELECT * FROM ". TB_CATEGORY ." WHERE Parent = ".$cat_id;
$results = MysqL_query($request);
while($child = MysqL_fetch_array($results))
{
deleteSub($child["CID"]);
}
$request = "DELETE FROM ". TB_CATEGORY ." WHERE CID = ".$cat_id;
return MysqL_query($request);
}
一种更好的方法是使用这种递归函数将CID存储在一个数组中,然后发出一个DELETE请求,但我认为你将能够调整这段代码.
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