如何獲取從循環中獲取的總行數？

Question

我做的，我希望得到總行數的一個PHP頁面，但它給我的結果爲零，我該怎麼總結NUM在PHP中的行，這裏是我的代碼：

<? 
$recepients=0; 
$count=count($_POST['events']); 
for($i=0; $i<$count; $i++){ 
    $select="select b.first_name AS first_name,b.last_name AS last_name from buyers b,registrations r where b.buyer_id=r.buyer_id and r.event_id='".$_POST['events'][$i]."' group by r.buyer_id"; 
    $res = $GLOBALS ['mysqli']->query ($select) or die ($GLOBALS ['mysqli']->error . __LINE__); 
    $record=mysqli_num_rows($res); 
} 
echo $recepients+=$record; 

?> 

Answer 1

嘗試添加到循環

<? 
    $recepients=0; 
    $count=count($_POST['events']); 
    for($i=0; $i<$count; $i++){ 
        $select="select b.first_name AS first_name,b.last_name AS last_name from buyers b,registrations r where b.buyer_id=r.buyer_id and r.event_id='".$_POST['events'][$i]."' group by r.buyer_id"; 
     $res = $GLOBALS ['mysqli']->query ($select) or die ($GLOBALS ['mysqli']->error . __LINE__); 
     $record=mysqli_num_rows($res); 

     $recepients = $recepients + $record; 
    } 
    echo $recepients; 

    ?> 

Answer 2

<? 
$recepients=0; 
$count=count($_POST['events']); 
for($i=0; $i<$count; $i++){ 
    $select="select b.first_name AS first_name,b.last_name AS last_name from buyers b,registrations r where b.buyer_id=r.buyer_id and r.event_id='".$_POST['events'][$i]."' group by r.buyer_id"; 
    $res = $GLOBALS ['mysqli']->query ($select) or die ($GLOBALS ['mysqli']->error . __LINE__); 
    $record = mysqli_num_rows($res); 
    $recepients += $record; // i think you're missing this 
} 
echo $recepients; // edited - forgot to edit this one. 
?> 

我覺得你只是錯過1行代碼。

Answer 3

計算應循環的內部完成，

$recepients = 0; 
    for($i=0; $i<$count; $i++){ 
      $select="select b.first_name AS first_name,b.last_name AS last_name from buyers b,registrations r where b.buyer_id=r.buyer_id and r.event_id='".$_POST['events'][$i]."' group by r.buyer_id"; 
      $res = $GLOBALS ['mysqli']->query ($select) or die ($GLOBALS ['mysqli']->error . __LINE__); 
      $record=mysqli_num_rows($res); 
      $recepients += $record; 
    } 
    echo $recepients;