Question

我需要一些帮助才能改进我目前的代码。我有一个巨大的阵列（里面有大约20,000个对象）。该数组如下所示：

  Array
(
    [0] => Player Object
        (
            [name] => Aaron Flash
            [level] => 16
            [vocation] => Knight
            [world] => Amera
            [time] => 900000
            [online] => 1
        )

    [1] => Player Object
        (
            [name] => Abdala da Celulose
            [level] => 135
            [vocation] => Master Sorcerer
            [world] => Amera
            [time] => 900000
            [online] => 1
        )

    [2] => Player Object
        (
            [name] => Ahmudi Segarant
            [level] => 87
            [vocation] => Elite Knight
            [world] => Amera
            [time] => 900000
            [online] => 1
        )

    [3] => Player Object
        (
            [name] => Alaskyano
            [level] => 200
            [vocation] => Royal Paladin
            [world] => Amera
            [time] => 900000
            [online] => 1
        )

    [4] => Player Object
        (
            [name] => Aleechoito
            [level] => 22
            [vocation] => Knight
            [world] => Amera
            [time] => 900000
            [online] => 1
        )

等等......总共约有20,000个玩家对象。

现在我想将它们全部插入到我的数据库中。我想找到一种不循环所有玩家的方法。它导致了很多性能问题，而且几乎导致我的计算机死机。我想一次性在一个查询中完成它。

但是如何获得Player Object属性，比如每个单独对象的“name”，“level”和“vocation”而不循环它们？

这就是我的代码：

// Insert player list to database
$sql = $db->prepare("INSERT INTO players (name, level, vocation, world, month, today, online) VALUES (:name, :level, :vocation, :world, :time, :time, :online) ON DUPLICATE KEY UPDATE level = :level, vocation = :vocation, world = :world, month = month + :time, today = today + :time, online = :online");

foreach ($players as $player) {
  $query = $sql->execute([
    ":name" => $player->name,
    ":level" => $player->level,
    ":vocation" => $player->vocation,
    ":world" => $player->world,
    ":time" => $player->time,
    ":online" => $player->online
  ]);
}

因为现在在底部的那个foreach上，它循环遍历我的数组中的20,000个玩家对象，并获得他们的名字/等级/职业/世界等等。

有更好的方法吗？我这样做的方式不是最好的解决方案。我可以听到我的电脑工作超载，感觉好像要崩溃了。

Answer 1

虽然我仍然怀疑交易和/或批量插入是解决资源使用问题的可行方案，但它们仍然比准备Dave建议的大量语句更好。

给他们一个镜头，看看他们是否有帮助。

以下假设PDO的错误处理模式设置为抛出异常。例如：$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);如果出于某种原因，您无法使用异常模式，那么您每次都需要检查execute()的返回并抛出您自己的异常。

单笔交易：

$sql = $db->prepare("INSERT INTO players (name, level, vocation, world, month, today, online) VALUES (:name, :level, :vocation, :world, :time, :time, :online) ON DUPLICATE KEY UPDATE level = :level, vocation = :vocation, world = :world, month = month + :time, today = today + :time, online = :online");

$db->beginTransaction();
try {
    foreach ($players as $player) {
        $sql->execute([
            ":name" => $player->name,
            ":level" => $player->level,
            ":vocation" => $player->vocation,
            ":world" => $player->world,
            ":time" => $player->time,
            ":online" => $player->online
        ]);
    }
    $db->commit();
} catch( PDOException $e ) {
    $db->rollBack();
    // at this point you would want to implement some sort of error handling
    // or potentially re-throw the exception to be handled at a higher layer
}

批量交易：

$batch_size = 1000;
for( $i=0,$c=count($players); $i<$c; $i+=$batch_size ) {
    $db->beginTransaction();
    try {
        for( $k=$i; $k<$c && $k<$i+$batch_size; $k++ ) {
            $player = $players[$k];
            $sql->execute([
                ":name" => $player->name,
                ":level" => $player->level,
                ":vocation" => $player->vocation,
                ":world" => $player->world,
                ":time" => $player->time,
                ":online" => $player->online
            ]);
        }
    } catch( PDOException $e ) {
        $db->rollBack();
        // at this point you would want to implement some sort of error handling
        // or potentially re-throw the exception to be handled at a higher layer
        break;
    }
    $db->commit();
}

Answer 2

我认为您将获得的最大性能提升是不对每个插入执行一次查询，而是对所有插入执行单个查询。类似的东西：

$sql = "INSERT INTO players (name, level, vocation, world, month, today, online) VALUES ";
$inserts = [];
$values = [];
$idx = 0;
foreach ($players as $player) {
    $idx++;
    $inserts[] = "(:name{$idx}, :level{$idx}, :vocation{$idx}, :world{$idx}, :month{$idx}, :today{$idx}, :online{$idx})";
    $values[":name{$idx}"] = $player->name;
    $values[":level{$idx}"] = $player->level;
    $values[":vocation{$idx}"] = $player->vocation;
    $values[":world{$idx}"] = $player->world;
    $values[":month{$idx}"] = $player->time;
    $values[":today{$idx}"] = $player->time;
    $values[":online{$idx}"] = $player->online;
}
$sql .= implode(",", $inserts);
$sql .= " ON DUPLICATE KEY UPDATE level = VALUES(level), vocation = VALUES(vocation), world = VALUES(world), month = month + VALUES(time), today = today + VALUES(time), online = VALUES(online)";

$query = $db->prepare($sql)->execute($values);

PDO - 将大型数组插入MySQL数据库

2 个答案: