PHP的問題有一個循環中的值的總和

Question

我是新來的PHP，並陷入循環。

我有以下：

• 含有0或沒有命名$receivers陣列。
• 另一個陣列包含總數爲接收器的數字，名稱爲$totalreceivers。
• 函數查詢帶有id的表，返回0或數字，名爲status()。

我想遍歷接收器的每個status()並在最後顯示總和。我無法得到它。

任何幫助將不勝感激。提前致謝。

這裏是我的嘗試：

for ($i = 0; $i < $totalreceivers; $i++) 
{ 
    $status = status($receivers[$i]); 
    foreach ($totalreceivers as $value) 
     $status = status($receivers[$i]); 
    echo "the sum of receiver having status different than 0 is"; 
    echo count($status); 
} 

function status($id) 
{ 
    global $dbhost; 
    global $dbuser; 
    global $dbpass; 
    global $dbname; 
    global $d1; 

    $q2 = mysql_query("select * from user where id ='$id' AND subscription_end_date IS NULL", $d1); 

    while($row2 = mysql_fetch_array($q2)) 
     $rowservice = $row2['value']; 
    return $rowservice; 
} 

Answer 1

可以簡化通過讓MySQL的爲你做更多的工作這一任務。

你有一個數組$receivers這大概包含id的訂戶（接收器）的東西。 （我可以互換使用接收方和用戶。）

status()函數從數據庫中檢索value，其中subscription_end_date爲空。我將假定每個用戶只有一行，因爲您只通過變量$rowservice返回最後一個結果。

從您的代碼中不清楚您是否想要使用value而不是0的接收器計數，或者是否需要所有非零值的總和。那麼問題是：

• 你想知道有多少訂戶有非零值？或者，
• 您是否想知道具有非零值的訂閱者的所有值的總和？

好在這兩個可以很容易地發現：

多少接收機具有非零值？

$allreceivers = implode(',', $receivers); 
$query = "SELECT COUNT(id) AS total_receivers 
    FROM user 
    WHERE subscription_end_date IS NULL 
    AND value != 0 
    AND id IN ($allreceivers);"; 
$result = mysql_query($query, $d1); 
$row = mysql_fetch_array($result); 
$total_receivers = $row['total_receivers']; 

echo "The number of receivers having status (value) other than 0 is $total_receivers"; 

什麼是所有接收值的總和？

$allreceivers = implode(',', $receivers); 
$query = "SELECT SUM(value) AS receiver_value_sum 
    FROM user 
    WHERE subscription_end_date IS NULL 
    AND id IN ($allreceivers);"; 
$result = mysql_query($query, $d1); 
$row = mysql_fetch_array($result); 
$receiver_value_sum = $row['receiver_value_sum']; 

echo "The sum of receiver values is $receiver_value_sum"; 

Answer 2

在代碼中有兩件事情沒有真正意義。首先，你嘗試兩次遍歷$totalreceivers，一個循環嵌套在另一個循環中。我懷疑這就是你想要的，所以你應該擺脫其中的一個。你的第一個循環有一個不好的表達式：在第一個for循環中遍歷$totalreceivers，你需要讓你的測試表達式與數組中元素的數量相反，而不是數組本身（可以使用count（））：for ($i = 0; $i < count($totalreceivers); $i++)。

其次，每當您在循環中呼叫status()時，您將重置$status的值。要添加到它，請使用+=運營商：$status += status($receivers[$i]);

第三，你在狀態（）函數$rowservice;重置該循環的每次迭代。要麼設置一次，要麼總結一下。

Answer 3

乍一看，它看起來像你只是在每次迭代覆蓋「$狀態」。在循環開始之前，將$ status設置爲一個空數組，然後在每次迭代時添加它。例如：

$status = array(); 
    foreach ($totalreceivers as $value) 
    { 
    $status[] = status($receivers[$i]); 
    } 
    echo count($status); 

Answer 4

我會盡力勾勒出下面的代碼可能出現的問題：

for ($i = 0; $i < $totalreceivers; $i++) { //This open bracket has no end bracket 
/*I assume total receivers is the number of receivers; if that is the case, it shouldn't be an array, but merely a value.*/ 
      $status = status($receivers[$i]); 
/*I think you should define the status function before you call it; also, if you are just calling the status function for each value of $receivers, why don't you just do a foreach($receivers as $value) loop, like you did below with $totalreceivers. */ 
     foreach ($totalreceivers as $value) 
/*I'm not sure what $totalreceivers is. You said its an array containing total number of receivers; again, I would think this would be a single value, and not an array*/ 
     { 
     $status = status($receivers[$i]); 
/*looks like you're calling the status function again*/ 
     } 
      echo "the sum of receiver having status different thant 0 is"; echo count($status); 
/* $status at this point would count the value from row2 for the last value in $receivers, and not a count of array values. Perhaps you could do $status[] = status($receivers[$i]), and then count($status) to save each value to an array, then count the elements. */ 

function status($id){ 
global $dbhost; 
global $dbuser; 
global $dbpass; 
global $dbname; 
/* The values above aren't used in the function; you may want to connect to the database outside of the function, before the foreach loop. */ 
global $d1 ; 

$q2 = mysql_query("select * from user where id ='$id' AND subscription_end_date IS NULL",$d1); 
while($row2 = mysql_fetch_array($q2)){ 
$rowservice = $row2['value']; 
} 
return $rowservice; 
} 
/*the rest looks good*/