$list = Db::table('fa_shopping')
->alias('a')
->join('fa_my2_commodity b', 'b.id = a.commodity_id')
->where('a.type', $type)
->where('a.user_id', $user_id)
if('a.status_type' == 1 ){
->field('b.name')
}else{
->field('a.name')
}
->select();
我想实现if中的效果 求具体写法