php - 在用 XML 提取 XML 中的欧洲央行汇率时遇到一些麻烦.. 有问题的完整源代码

Question

我需要获取内部会计系统的历史汇率引用率列表。

这个问题仅与以下代码有关，如果您觉得它有用，请随意使用此代码(当然，一旦我们得到解决最终“小问题”的答案。我在代码中包含了一个 DB 结构转储，所有 DB例程被注释掉，现在只是回显调试数据。

数据取自欧洲中央银行 XML，网址为 http://www.ecb.europa.eu/stats/eurofxref/eurofxref-hist.xml

固定的!如果您需要将历史汇率值列表拉入数据库，请随意使用此代码..确保删除 echo 调试并整理数据库查询

<?php

/* DB structure:
 CREATE TABLE IF NOT EXISTS `currency_rates_history` (
  `id` int(4) NOT NULL auto_increment,
  `currency` char(3) character set utf8 collate utf8_unicode_ci NOT NULL default '',
  `rate` float NOT NULL default '0',
  `date` int(4) NOT NULL default '0',
  `est` tinyint(1) NOT NULL,
  PRIMARY KEY  (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8_unicode_ci AUTO_INCREMENT=1 ;

*/

error_reporting(E_ALL);

$table = "currency_rates_history";

$secs = '86400';

$prev_date = time();

$days = "0";

$XML=simplexml_load_file("http://www.ecb.europa.eu/stats/eurofxref/eurofxref-hist.xml");    // European Central Bank xml only contains business days! oh well....


foreach($XML->Cube->Cube as $time)                                                          // run first loop for each date section
{

    echo "<h1>".$time["time"].'</h1>';

    list($dy,$dm,$dd) = explode("-", $time["time"]);

    $date = mktime(8,0,0,$dm,$dd,$dy);

    echo ($prev_date - $date)."<br />";

    if(($prev_date - $date) > $secs)                                                        // detect missing weekend and bank holiday values.
    {

        echo "ooh";                                                                         // for debug to search the output for missing days

        $days =(round((($prev_date - $date)/$secs),0)-1);                                   // got to remove 1 from the count....

        echo $days;                                                                         // debug, will output the number of missing days

    }
    foreach($time->Cube as $_rate)                                              // That fixed it! run the 2nd loop and ad enter the new exchange values....
    {

        $rate = floatval(str_replace(",", ".", $_rate["rate"]));


        if($days > 0)                                                                       // add the missing dates using the last known value, coul dbe more accurate but at least there is some reference data to work with
        {
            $days_cc = $days;                                                               // need to keep $days in mem for the next currency

            while($days_cc > 0)
            {
                echo $rate;
                echo date('D',$date+($days_cc*$secs))."<br />";
                /*
                mysql_query("LOCK TABLES {$table} WRITE");

                mysql_query("INSERT INTO {$table}(rate,date,currency,est) VALUES('{$rate}','".($date+($days_cc*$secs))."','{$currency}','1')");

                mysql_query("UNLOCK TABLES");
                */
                $days_cc = ($days_cc - 1);  // count down
            }
        }

        $currency = addslashes(strtolower($_rate["currency"]));
        /*
        mysql_query("LOCK TABLES {$table} WRITE");
//      mysql_query("UPDATE {$table} SET rate='{$rate}',date='{$date}' WHERE currency='{$currency}' AND date='{$date}'");   // all this double checking was crashing the script
//      if (mysql_affected_rows() == 0)
//      {
            mysql_query("INSERT INTO {$table}(rate,date,currency) VALUES('{$rate}','{$date}','{$currency}')");              // so just insert, its only going to be run once anyway!
//      }

        mysql_query("UNLOCK TABLES");
        */

        echo "1&euro;=  ".$currency."   ".$rate.", date:   ".date('D d m Y',$date)."<br/>";
    }
          $days="";                                                                         // clear days value
    $prev_date = $date;                                                                     // store the previous date
}

echo "<h1>Currencies Saved!</h1>";
?>

所以..... 问题出在第二个 foreach 循环中:foreach($XML->Cube->Cube->Cube as $_rate)，如果您尝试运行该脚本，您会注意到日期是正确的，它会处理很好地缺少周末和银行假期日期，但利率值只引用 XML 中的最新利率，即今天的值。

它应该从 XML 中的相关区域中提取数据，即给定日期的费率......但事实并非如此。这是 simplexml_load_file 中的问题还是我在代码中遗漏了一些愚蠢的东西？头现在开始疼，所以要休息一下。新鲜的眼睛是最受欢迎的!

Answer 1

$XML->Cube->Cube->Cube在第二个循环中:$XML->Cube->Cube总是指第一个二级cube在第一级cube .所以你正在迭代第三级 cubes在同一个元素中。因此，您只得到今天的费率。有道理？

试试这个。我已经修改了您的命令行输出代码，而不是 html。唯一的主要变化是在第二个 foreach陈述...

$XML=simplexml_load_file("http://www.ecb.europa.eu/stats/eurofxref/eurofxref-hist.xml");
foreach($XML->Cube->Cube as $time){
    echo "----".$time["time"]. "----\n";
    foreach($time->Cube as $_rate){
        $rate = floatval(str_replace(",", ".", $_rate["rate"]));
        $currency = addslashes(strtolower($_rate["currency"]));
        echo "1 euro =  ".$currency."   ".$rate . "\n";
    }
    echo "------------------\n\n";
}
echo "Done!";