ecshop 获取分类下商品是数量

//获取分类下面商品是数量
function get_child_tree_goods_number($cat_id)
{
    //调用小分类的商品数量
    //$sql = 'SELECT count(goods_id) as number  FROM ' . $GLOBALS['ecs']->table('goods') . " as g WHERE  is_on_sale =  is_alone_sale  AND is_delete = 0 AND   (g.cat_id IN (select cat_id from ". $GLOBALS['ecs']->table('category') ."  where parent_id = $cat_id or cat_id = $cat_id )  OR " . get_extension_goods($cat_id) . ')';
    $sql =  'select count(goods_id) as number FROM  ' . $GLOBALS['ecs']->table('goods') . " as g  right join  ". $GLOBALS['ecs']->table('category') ."  as c on g.cat_id = c.cat_id  where  g.is_on_sale = 1 AND g.is_alone_sale = 1  AND g.is_delete = 0 AND (c.parent_id = $cat_id  or c.cat_id = $cat_id)";
    //只调用当前分类的商品数量
    //$sql = 'SELECT count(*) as number  FROM ' . $GLOBALS['ecs']->table('goods') . " as g WHERE  is_on_sale = 1 AND is_alone_sale = 1 AND is_delete = 0 AND   g.cat_id  = $cat_id  ";
    return $GLOBALS['db']->getOne($sql);
}