Problem beim Hinzufügen von Datenbankeinträgen mit THINKPHP3?

Question

if ($cart_info) {

$data['num'] = intval($cart_info['num'])+intval($num);

//判断库存

if (intval($check_info[' num'])<=$data['num']) {

echo json_encode(array('status'=>0,'err'=>'库存不足！'));

exit;

}

$res = $shpp->where('id='.intval($cart_info['id']))->save($data);

}else{

$data[' pid']=intval($pid);

$data['num']=intval($num);

$data['addtime']=time();

$data['uid']= intval($uid);

$data['shop_id']=intval($check_info['shop_id']);

$ptype = 1;

if (intval($check_info['pro_type'])) {

$ptype = intval($check_info['pro_type']);

}

$data['type']=$ptype;

$data['price'] = $check_info['price_yh'];

            $data['aa']='增加'

$res=$shpp->add($data);

}

if($res){

echo json_encode(array( 'status'=>1,'cart_id'=>$res)); //该商品已成功加入您的购物车

exit;

}else{

echo json_encode(array('status'=>0,'err'=>'加入失败.'));

beenden;

}

$res=$shpp->add($data);增加记录后后返回ID=1

但我的数据库ID值却为5 ，

数据库的ID 没有与新增的记录同步。