摘要：環(huán)境適用場(chǎng)景需要處理一定數(shù)據(jù)集業(yè)務(wù)從讀取一定數(shù)據(jù)的業(yè)務(wù)導(dǎo)出一次需要處理一定的業(yè)務(wù)操作更新刪除等更多需要處理一定數(shù)據(jù)集的操作關(guān)鍵設(shè)置關(guān)鍵設(shè)置，如果不設(shè)置，依舊會(huì)從一次取出數(shù)據(jù)到里的游標(biāo)屬性不是必須的生成器生成器，迭代數(shù)據(jù)操作本生成器可

mysql: 5.6.34
php: 5.6
nginx: php-fpm

需要處理一定數(shù)據(jù)集業(yè)務(wù)

從mysql讀取一定數(shù)據(jù)的業(yè)務(wù)導(dǎo)出

一次需要處理一定的mysql業(yè)務(wù)操作更新刪除等

更多需要處理一定數(shù)據(jù)集的操作

$dbh = new PDO($dsn, $user, $pass);
# 關(guān)鍵設(shè)置，如果不設(shè)置，php依舊會(huì)從pdo一次取出數(shù)據(jù)到php
$dbh->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, false);
//perpare里的游標(biāo)屬性不是必須的
$sth = $dbh->prepare("SELECT * FROM `order`", array(PDO::ATTR_CURSOR => PDO::CURSOR_SCROLL));
$sth->execute();

生成器，迭代數(shù)據(jù)操作
本生成器可省略

class Test {
    public function test()
    {
        set_time_limit(0);
        $dbms="mysql";     //數(shù)據(jù)庫(kù)類型
        $host=C("DB_HOST"); //數(shù)據(jù)庫(kù)主機(jī)名
        $dbName=C("DB_NAME");    //使用的數(shù)據(jù)庫(kù)
        $user=C("DB_USER");      //數(shù)據(jù)庫(kù)連接用戶名
        $pass=C("DB_PWD");          //對(duì)應(yīng)的密碼
        $dsn="$dbms:host=$host;dbname=$dbName";
        $dbh = new PDO($dsn, $user, $pass);
        $dbh->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, false);
        $sth = $dbh->prepare("SELECT * FROM `order`");
        $sth->execute();
        $i = 0;

        $newLine = PHP_SAPI == "cli" ? "
" : "
";

        foreach ($this->cursor($sth) as $row) {
//            var_dump($row);
            echo $row["id"] . $newLine;
            $i++;
        }

        echo "消耗內(nèi)存：" . (memory_get_usage() / 1024 / 1024) . "M" . $newLine;
        echo "處理數(shù)據(jù)行數(shù)：" . $i . $newLine;
        echo "success";
    }

    public function cursor($sth)
    {
        while($row = $sth->fetch(PDO::FETCH_ASSOC)) {
            yield $row;
        }
    }
}

$test = new Test();
$test->test();

1
... //省略部分id
804288
消耗內(nèi)存："0.34918212890625M
處理數(shù)據(jù)行數(shù)：254062
success