PHP生成不正確的算術結果

我有一個PHP腳本，它啓動一個mysql查詢並返回一個結果集合的列。PHP生成不正確的算術結果

我需要對這些列進行進一步的聚合，並且正如我在腳本中所做的那樣。

問題是，對於20個限制中的前7個結果，計算公然不正確。

這是否與桌子很大的事實有關？（3.5m行）

我可以在SQL級別完成額外的聚合嗎？說A是一個聚合和B是一個聚合，我可以做C = B/A？

//QUERY 
     $resultsquery = $db->prepare("SELECT 4_nationality.nationality, COUNT(DISTINCT(txn_id)) as numtrans, 
             SUM(sales) as sales, SUM(units) as units, YrQtr 
             FROM 1_txns INNER JOIN 4_nationality USING (nationality_id) 
             WHERE YrQtr LIKE :period 
             GROUP BY nationality_id 
             ORDER BY numtrans DESC 
             LIMIT 20"); 
     $resultsquery->bindParam(":period", $period); 
     $resultsquery->execute(); 

     //BUILD TABLE 

     echo "<div class='col-xs-12 col-sm-10'>"; 
     echo $select; 


     echo "<table class='table table-striped'><tr>"; 
      echo "<th>Nationality</th>"; 
      echo "<th># Trans</th>"; 
      echo "<th>Sales</th>"; 
      echo "<th>Units</th>"; 
      echo "<th>ATV</th>"; 
      echo "<th>UPB</th>"; 
      echo "<th>ARP</th>"; 
     echo "</tr>"; 

     while($row2 = $resultsquery->fetch(PDO::FETCH_ASSOC)){ 

      //FURTHER CALCULATIONS 

      $nat = $row2['nationality']; 
      $numtrans = number_format($row2['numtrans'], 0); 
      $sales = number_format($row2['sales'], 0); 
      $units = number_format($row2['units'], 0); 
      $atvc = $sales/$numtrans; 
      $atv = number_format($atvc, 2); 
      $upbc = $units/$numtrans; 
      $upb = number_format($upbc, 1); 
      $arpc = $sales/$units; 
      $arp = number_format($arpc, 2); 

       //DISPLAY 
       echo "<tr>"; 
        echo "<td>".$nat."</td>"; 
        echo "<td>".$numtrans."</td>"; 
        echo "<td>".$sales."</td>"; 
        echo "<td>".$units."</td>"; 
        echo "<td>".$atv."</td>"; 
        echo "<td>".$upb."</td>"; 
        echo "<td>".$arp."</td>"; 
       echo "</tr>"; 

     } 

     echo "</table>"; 
     echo "</div>";

編輯：非常感謝這兩個問題的答案，這是很難選擇哪一個接受，因爲他們都幫助我以不同的方式。然而，我決定接受提供有關問題標題更多細節的答案。

來源

2016-01-27 Adam Copley

這可能是因爲您正在對格式化的字符串執行算術運算。

嘗試：

$nat = $row2['nationality']; 
$numtrans = number_format($row2['numtrans'], 0); 
$sales = number_format($row2['sales'], 0); 
$units = number_format($row2['units'], 0); 
$atvc = $row2['sales']/$row2['numtrans']; 
$atv = number_format($atvc, 2); 
$upbc = $row2['units']/$row2['numtrans']; 
$upb = number_format($upbc, 1); 
$arpc = $row2['sales']/$row2['units']; 
$arp = number_format($arpc, 2);

編輯：

其實我敢肯定，這是什麼happenning：

echo '15,263,316'/'568,393'; // 0.026408450704225 
echo 15263316/568393;  //26.853455267746

來源

2016-01-27 17:01:31 Flosculus

它沒有工作，因爲你用格式的數字像27,002,864計算而不是27002864。是的，在SQL中更容易：

SELECT 4_nationality.nationality, COUNT(DISTINCT(txn_id)) as numtrans, 
    SUM(sales) as sales, SUM(units) as units, YrQtr, 
    sum(sales)/count(distinct txn_id) atvc, 
    sum(units)/count(distinct txn_id) upbc, 
    sum(sales)/sum(units) arp 
FROM 1_txns INNER JOIN 4_nationality USING (nationality_id) 
WHERE YrQtr LIKE :period 
GROUP BY nationality_id 
ORDER BY numtrans DESC 
LIMIT 20

來源

2016-01-27 17:04:59 Fabricator

PHP生成不正確的算術結果

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