Laravel雄辩的belongsto在列中使用逗号分隔的多个id

我有

媒体、媒体类型、媒体地图和国家。

country with field id, name, created_at, updated_at.

media_type with field id, name, created_at, updated_at.

media table with field id, name, media_type_id, description, created_at, updated_at.

media_mapping with field id, media_id,country_id, hastags, created_at, updated_at.

country_id包含逗号分隔的id,如1,2,3,4来自country

我试过下面的代码,它给出了逗号分隔列的错误。

$mediaQuery = new Media();
$mediaQuery = $mediaQuery->newQuery();
$mediaQuery->orderBy('created_at', 'desc')
->with(array('MediaMapping'=>function($query){
    $query->select('media_id', 'country_id', 'hashtags')->with(array('Country'=>function($query){
        $query->select('id','name');
    }
));
},
'MediaType'=>function($query){
    $query->select('id','name');
})
);
$allDataList = $mediaQuery->get();

“SQLSTATE[22P02]:无效的文本表示:7错误:无效输入