Shock

<?php
function generateData ($size, $depth, $parent) {
    $result = array();
    for ($i = 0; $i < $size; $i++) {
        $elem = new Elem;
        $elem->setData ($parent ? $parent->getData() . '.' . ($i+1) : '#'.($i+1));
        $elem->setChildren ($depth ? generateData($size, $depth-1, $elem) : array());
        $elem->setParent ($parent);
        $result[] = $elem;
    }
    return $result;
}

function insertTreeRecursive ($tree) {
    $qElem = "INSERT INTO `Elements` (`ID`, `Data`) VALUES (NULL, '%s')";
    $qHier = "INSERT INTO `ElementsHierarchy`(`ElemID`,`ParentID`,`Level`) VALUES (%s)";
    $qParents = "SELECT * FROM `ElementsHierarchy` WHERE `ElemID` = '%d'";
    foreach ($tree as $elem) {
        $query   = sprintf($qElem, Db::escape($elem->getData()));
        $elem->setId(Db::execute($query));
        $parents = array();
        if ($elem->getParent()) {
            $parentId = $elem->getParent()->getId();
            $parentParents = Db::select(sprintf($qParents, $parentId));
            foreach ($parentParents as $k => $v) {
                $parents[] = join (',', array ($elem->getId(), $v['ParentID'] ? $v['ParentID'] : 'NULL', $v['Level']+1));
            }
            $parents[] = join (',', array ($elem->getId(), $parentId, 1));
            $parentsString = join ('), (', $parents);
        } else {
            $parentsString = join (',', array($elem->getId(), 'NULL', 1));
        }
        Db::execute(sprintf($qHier, $parentsString));
        if ($elem->getChildren()) {
            insertTreeRecursive($elem->getChildren());
        }
    }
}

function getRowsByParent ($id) {
    $id = (int) $id;
    return Db::select("
SELECT * FROM `Elements`
INNER JOIN `ElementsHierarchy` as `Hier`
    ON `Hier`.`ElemID` = `Elements`.`ID`
WHERE
    `Hier`.`ParentID` = '$id' OR
    `Elements`.`Id` = '$id'
GROUP BY `Elements`.`Id`
    ");
}

function getTreeByParent ($id) {
    $where = !is_int($id) ? '' :
        "WHERE `Hier`.`ParentID` = $id OR `Elements`.`Id` = $id";
    $rows = Db::select("
SELECT `Elements`.*, `Parent`.`ParentID` FROM `Elements`
INNER JOIN `ElementsHierarchy` as `Hier`
    ON `Hier`.`ElemID` = `Elements`.`ID`
INNER JOIN `ElementsHierarchy` as `Parent`
    ON (`Parent`.`ElemID` = `Elements`.`ID` AND `Parent`.`Level` = 1)
    " . $where);
    $tree = createElem($id);
    foreach ($rows as $r) {
        $parent = createElem($r['ParentID']);
        $elem   = createElem($r['ID']);
        $elem->setData($r['Data']);
        $elem->setParent($parent);
        $parent->addChild($elem);
    }
    return $tree;
}

function createElem ($id) {
    static $elements = array ();
    if (empty($elements[$id])) {
        $elem = new Elem;
        $elem->setId($id);
        $elements[$id] = $elem;
    }
    return $elements[$id];
}


function markTreeByParent ($id, $value) {
    $value = (int) $value;
    $where = !is_int($id) ? '' :
        "WHERE `Hier`.`ParentID` = $id OR `Elements`.`Id` = $id";
    Db::execute("
UPDATE `Elements`
INNER JOIN `ElementsHierarchy` as `Hier`
    ON `Hier`.`ElemID` = `Elements`.`ID`
SET `Elements`.`Marked` = '$value'
    " . $where);
}