$good=$cart->field("goods_id")->where("member_id='$mid'")->select();
这个查询出来的不是一维数组,是个二维数组。
类似
[
0=>["goods_id"=>1],
1=>["goods_id"=>2],
.....
];
可以这么写
$goods_ids=$cart->where("member_id='$mid'")->getField("goods_id");
$com=$commodite->where(["id"=>["in",$goods_ids]])->select();