mysqli::query(）:无法'；t在foreach循环的第一行之后获取mysqli - mysqli::query(): Couldn't fetch mysqli after first line of foreach loop

mysqli::query(): Couldn't fetch mysqli after first line of foreach loop

我创建了一个foreach循环来将数据添加到MySQL数据库，在将第一行添加到数据库后，我收到错误"mysqli:：query((：无法获取mysqli"。

PHP-DB连接

$db = new mysqli($db_hostname, $db_username, $db_password, $db_database);
if ($db->connect_error) {
    die("Connection failed: " . $db->connect_error);
}

然后我有另一块脚本，它收集我需要的数据。然后将数据添加到foreach插入循环

PHP FOREACH

foreach($RSS_DOC->channel->item as $RSSitem)
{
    $item_id    = md5($RSSitem->title);
    $fetch_date = date("Y-m-j G:i:s"); 
    $item_title = $RSSitem->title;
    $item_date  = date("Y-m-j G:i:s", strtotime($RSSitem->pubDate));
    $item_url   = $RSSitem->link;
    echo "Processing item '" , $item_id , "' on " , $fetch_date     , "<br/>";
    echo $item_title, " - ";
    echo $item_date, "<br/>";
    echo $item_url, "<br/>";
    $sql = "INSERT INTO rssingest (item_id, feed_url, item_title, item_date, item_url, fetch_date) 
    VALUES ('" . $item_id . "', '" . $feed_url . "', '" . $item_title . "', '" . $item_date . "', '" . $item_url . "', '" . $fetch_date . "')";
    if ($db->query($sql) === TRUE) {   // <- THIS IS LINE 170
        echo "New record created successfully";
    } else {
    echo "Error: " . $sql . "<br>" . $db->error;
    }
    $db->close();
}

第一行被添加到数据库中，没有任何问题。第二行和之后的每一行都返回"mysqli:：query((：无法在第170行获取mysqli"。

有什么想法我可能会出错吗？

问题可能是循环中的$db->close()。请尝试在循环后关闭数据库。

    foreach($RSS_DOC->channel->item as $RSSitem)
{
    $item_id    = md5($RSSitem->title);
    $fetch_date = date("Y-m-j G:i:s"); 
    $item_title = $RSSitem->title;
    $item_date  = date("Y-m-j G:i:s", strtotime($RSSitem->pubDate));
    $item_url   = $RSSitem->link;
    echo "Processing item '" , $item_id , "' on " , $fetch_date     , "<br/>";
    echo $item_title, " - ";
    echo $item_date, "<br/>";
    echo $item_url, "<br/>";
    $sql = "INSERT INTO rssingest (item_id, feed_url, item_title, item_date, item_url, fetch_date) 
    VALUES ('" . $item_id . "', '" . $feed_url . "', '" . $item_title . "', '" . $item_date . "', '" . $item_url . "', '" . $fetch_date . "')";
    if ($db->query($sql) === TRUE) {
        echo "New record created successfully";
    } else {
    echo "Error: " . $sql . "<br>" . $db->error;
    }

}
$db->close();