MySQL：在一个查询中选择类别和所有相关的子类别

Question

Hy，我有2个表，categories(id, name, slug)和subcategories(id, name, slug, category)。

我需要获取所有类别+子类别，但作为数组＆＃39;字段＆＃39;。我现在的询问是

SELECT c.id AS catId, c.name AS catName, c.slug AS catSlug, s.id AS subcatId, s.name AS subcatName, s.slug AS subcatSlug
FROM categories AS c
LEFT JOIN subcategories AS s ON c.id = s.category

结果就是这个

Array
(
    [0] => stdClass Object
        (
            [catId] => 5
            [catName] => calzature
            [catSlug] => calzature
            [subcatId] => 10
            [subcatName] => eleganti
            [subcatSlug] => eleganti
        )

    [1] => stdClass Object
        (
            [catId] => 5
            [catName] => calzature
            [catSlug] => calzature
            [subcatId] => 11
            [subcatName] => sportive
            [subcatSlug] => sportive
        )

    ....

)

我想将它们分组如下

Array
    (
        [0] => stdClass Object
            (
                [catId] => 5
                [catName] => calzature
                [catSlug] => calzature
                [subcategories] => array(
                    [0] => array(
                        [subcatId] => 1,
                        [subcatName] => Subcategory name,
                        [subcatSlug] => subcategory-slug,
                    ),
                    [1] => array(
                        [subcatId] => 2,
                        [subcatName] => Another Subcategory name,
                        [subcatSlug] => another-subcategory-slug,
                    ),
                    .....
                )
            )

我的目标是创建一个下拉菜单，其中主<li>是类别名称，辅助<li>是子类别。

如果可能，我如何在一个查询中完成此操作？

谢谢。