while和foreach循环与数组

Question

我正在为我的项目制作推车。 首先，访客（未登录）将从存储在SESSIONS中的类别中选择产品。 其次，访客将登录。我希望将SESSION中的所有项目存储在用户数据库中，或者如果存在，则进行更新。

这是我的代码：

while($row = $query->fetch(PDO::FETCH_ASSOC)) {

    //Log
    $core->testLog("Database Product: " . $row['product_id']);
    foreach($_SESSION['product_checkout_list'] as $key => $value) {

        //Log
        $core->testLog("- Array Product: " . $_SESSION['product_checkout_list'][$key]['checkID']);
        if($value['checkID'] == $row['product_id']) {
            $insert = $core->prepare("UPDATE on_cart SET user_id = :uid, qty = :qty, stamp = :stamp WHERE product_id = :prod_id");

            $insert->bindParam(":uid", $_SESSION['user']['id']);
            $insert->bindParam(":prod_id", $value['checkID']);
            $insert->bindParam(":qty", $value['checkQty']);
            $insert->bindparam(":stamp", $timestamp);
            $insert->execute();

            //Log
            $core->testLog("-- " . $value['checkID'] . " is equal to " . $row['product_id']);
        } else {
            $insert = $core->prepare("INSERT INTO on_cart VALUES(null, :uid, :prod_id, :qty, :stamp);");
            $insert->bindParam(":uid", $_SESSION['user']['id']);
            $insert->bindParam(":prod_id", $value['checkID']);
            $insert->bindParam(":qty", $value['checkQty']);
            $insert->bindparam(":stamp", $timestamp);
            $insert->execute();

            //Log
            $core->testLog("-- " . $value['checkID'] . " is not equal to " . $row['product_id']);

        }

        unset($_SESSION['product_checkout_list'][$key]);

            // Log
            foreach($_SESSION['product_checkout_list'] as $key => $value) {
                $core->testLog("--- " . $value['checkID']);
            }

        break;
    }
}

我的日志是这样的：

03/20/2018 - 10:36:21 PM : Database Product: 1
03/20/2018 - 10:36:21 PM : - Array Product: 1
03/20/2018 - 10:36:21 PM : -- 1 is equal to 1
03/20/2018 - 10:36:21 PM : --- 2
03/20/2018 - 10:36:21 PM : --- 4
03/20/2018 - 10:36:21 PM : Database Product: 2
03/20/2018 - 10:36:21 PM : - Array Product: 2
03/20/2018 - 10:36:21 PM : -- 2 is equal to 2
03/20/2018 - 10:36:21 PM : --- 4

我的问题是最后一个产品4-由于中断而被跳过。 但是，如果删除中断，则不会刷新$row['product_id'] （它将保持为1，直到所有操作完成）。 像这样：

03/20/2018 - 10:38:57 PM : Database Product: 1
03/20/2018 - 10:38:57 PM : - Array Product: 1
03/20/2018 - 10:38:57 PM : -- 1 is equal to 1
03/20/2018 - 10:38:57 PM : --- 2
03/20/2018 - 10:38:57 PM : --- 4
03/20/2018 - 10:38:57 PM : - Array Product: 2
03/20/2018 - 10:38:57 PM : -- 2 is not equal to 1
03/20/2018 - 10:38:57 PM : --- 4
03/20/2018 - 10:38:57 PM : - Array Product: 4
03/20/2018 - 10:38:57 PM : -- 4 is not equal to 1
03/20/2018 - 10:38:57 PM : Database Product: 2

我想做的是，访客或用户可以在登录之前先选择他们的产品。如果用户已经登录，系统将检查用户是否在SESSION购物车上有物品并将其插入数据库或更新现有的物品。 我两天前一直在考虑解决方案，但无法解决。 谢谢！

Answer 1

尽量避免在开关块以外的任何地方使用break。

此外，您正在以相反的方式进行搜索。 您需要针对阵列中的每个产品，检查它是否在数据库中。 看一看：

// Will only populate an array for easier search
$dbItems = array();
while($row = $query->fetch(PDO::FETCH_ASSOC)) {
    $dbItems[] = $row;
}

//Log
foreach($_SESSION['product_checkout_list'] as $key => $value) {

    //Log
    $core->testLog("- Array Product: " . $_SESSION['product_checkout_list'][$key]['checkID']);
    // Flag to mark if the item is on the db or not
    $found = false;

    foreach($dbItems as $row) {
        if($value['checkID'] == $row['product_id']) {
            $insert = $core->prepare("UPDATE on_cart SET user_id = :uid, qty = :qty, stamp = :stamp WHERE product_id = :prod_id");

            $insert->bindParam(":uid", $_SESSION['user']['id']);
            $insert->bindParam(":prod_id", $value['checkID']);
            $insert->bindParam(":qty", $value['checkQty']);
            $insert->bindparam(":stamp", $timestamp);
            $insert->execute();

            //Log
            $core->testLog("-- Found " . $value['checkID'] . " in db as " . $row['product_id']);
            // Flag it as found, so we will not insert it
            $found = true;
        } 
    }
    // Not found on the db? Lets insert it
    if(!$found) {
        $insert = $core->prepare("INSERT INTO on_cart VALUES(null, :uid, :prod_id, :qty, :stamp);");
        $insert->bindParam(":uid", $_SESSION['user']['id']);
        $insert->bindParam(":prod_id", $value['checkID']);
        $insert->bindParam(":qty", $value['checkQty']);
        $insert->bindparam(":stamp", $timestamp);
        $insert->execute();

        //Log
        $core->testLog("-- Product " . $value['checkID'] . " was not on the db");

    }
}

// Empty the session array
$_SESSION['product_checkout_list'] = array();