CakePHP 3 中的子查询?

Subqueries in CakePHP 3?

根据 CakePHP BelongsToMany 约定,我有两个 table productsproduct_categories 通过第三个 table、products_categories_products 关联(编辑: 这些协会建立在 ProductsTable.phpProductCategoriesTable.php)。我想生成一个产品类别列表,使用最畅销产品的图像来代表每个类别。

我可以使用以下函数实现我想要的结果:

public function findImages(Query $query, array $options) {
    $query->select([
        'ProductCategories.id',
        'ProductCategories.name',
        'ProductCategories__image' => '(SELECT Products.image
        FROM product_categories_products AS ProductCategoriesProducts
        LEFT JOIN products AS Products
        ON ProductCategoriesProducts.product_id = Products.id
        WHERE ProductCategoriesProducts.product_category_id = ProductCategories.id
        ORDER BY Products.turnover DESC
        LIMIT 1)'
    ])->where([
        'ProductCategories.name <>' => 'Unsorted'
    ])->order([
        'ProductCategories.name'    => 'asc'
    ]);
    return $query;
}

这是接受table还是有更简单的方法来实现我的目标?我真的找不到任何关于在 CakePHP 3 中制作子查询的主题。经过几个小时的挫折,我只是偶然发现了上述解决方案。任何建议表示赞赏!

感谢用户 ndm_yesterday 的 link,我生成了以下解决方案:

public function findImages(Query $query, array $options) {
    $this->hasMany('ProductCategoriesProducts');

    $subquery = $this->ProductCategoriesProducts->find('all')->select([
        'Products.image'
    ])->join([
        [
            'table'     => 'products',
            'alias'     => 'Products',
            'type'      => 'LEFT',
            'conditions'=> [
                'ProductCategoriesProducts.product_id = Products.id'
            ]
        ]
    ])->where([
        'ProductCategoriesProducts.product_category_id = ProductCategories.id'
    ])->order([
        'Products.turnover' => 'DESC'
    ])->limit(1);

    $query->select([
        'ProductCategories.id',
        'ProductCategories.name',
        'ProductCategories__image' => $subquery
    ])->where([
        'ProductCategories.name <>' => 'Unsorted'
    ])->order([
        'ProductCategories.name'    => 'asc'
    ]);

    return $query;
}