我的sql查询如下：

SELECT a.number, a.description,
       MAX(CASE WHEN b.attribute_code = 'brand' then b.attribute_value END) as brand,
       MAX(CASE WHEN b.attribute_code = 'model' then b.attribute_value END) as model,
       MAX(CASE WHEN b.attribute_code = 'category' then b.attribute_value END) as category,
       MAX(CASE WHEN b.attribute_code = 'subcategory' then b.attribute_value END) as subcategory
FROM items a JOIN
     attr_maps b
     ON b.number = a.number
GROUP BY a.number, a.description
HAVING brand = 'honda'

如果执行了查询，它就会工作
我想把sql查询转换成laravel查询
我试着这样：

$query = Item::selectRaw("a.number, a.description, MAX(CASE WHEN b.attribute_code = 'brand' then b.attribute_value END) as brand, MAX(CASE WHEN b.attribute_code = 'model' then b.attribute_value END) as model, MAX(CASE WHEN b.attribute_code = 'category' then b.attribute_value END) as category, MAX(CASE WHEN b.attribute_code = 'subcategory' then b.attribute_value END) as subcategory")
        ->from('items as a')
        ->join('attr_maps as b','b.number','=','a.number')
        ->groupBy('a.number');
foreach($param as $key => $value) {
    $query = $query->havingRaw("$key = $value");
}
$query = $query->orderBy('description')
        ->paginate(10);
return $query;

如果执行查询，则存在如下错误：

SQLSTATE[42S22]: Column not found: 1054 Unknown column 'brand' in 'having clause' (SQL: select count(*) as aggregate from `items` as `a` inner join `attr_maps` as `b` on `b`.`no` = `a`.`no` group by `a`.`no` having brand = honda)

如何解决错误？
笔记
结果 echo '<pre>';print_r($param);echo '</pre>';die(); :

Array
(
    [brand] => honda
    [model] => pcx
    [category] => test1
    [subcategory] => test2
)

更新
我必须找到解决办法。它是这样的：

public function list($param) 
{
    $brand = "MAX(CASE WHEN b.attribute_code = 'brand' then b.attribute_value END)";
    $model = "MAX(CASE WHEN b.attribute_code = 'model' then b.attribute_value END)";
    $category = "MAX(CASE WHEN b.attribute_code = 'category' then b.attribute_value END)";
    $subcategory = "MAX(CASE WHEN b.attribute_code = 'subcategory' then b.attribute_value END)";

    $query = Item::selectRaw("a.number, a.description, {$brand} as brand, {$model} as model, {$category} as category, {$subcategory} as subcategory")
            ->from('items as a')
            ->join('item_attr_maps as b','b.number','=','a.number')
            ->groupBy('a.number');

    foreach($param as $key => $value) {
        $query = $query->havingRaw("{$$key} = ?", [$value]);
    }

    $query = $query->orderBy('description')
            ->paginate(self::ITEM_PER_PAGE);

    return $query;
}