我在MySQL中有父类ID的类别列表.如何从列表中创建PHP数组.
ID Category Parent_ID
1 Car NULL
2 Education NULL
3 Mathematics 2
4 Physics 2
5 Astrophysics 4
array(
"Car" => "1",
"Education" => array("Mathematics" => "2", "Physics" => array("Astrophysics" => "4"))
);
事实上,键/值并不重要,因为我也会使用其他列.我只想知道如何扫描列表并生成多级列表.
解决方法:
一些非常简单的递归来构建树结构:
function buildTree(array $data, $parent = null) {
$branch = array();
foreach ($data as $row) {
if ($row['parent_id'] == $parent) {
$row['children'] = buildTree($data, $row['id']);
$branch[] = $row;
}
}
return $branch;
}
$tree = buildTree($rowsFromDatabase);
拥有明确的“子”键通常比您提出的结构更可取,但可以根据需要随意修改.