Question

我是php的新手并且陷入困境。

我有以下内容：

包含0或未命名为$receivers的数组。
另一个包含接收器的数组，这个接收器是一个名为$totalreceivers。
查询具有id的表的函数，返回0或数字，名为status()。

我想遍历接收器的每个status()并在结尾显示总和。我无法得到它。

任何帮助将不胜感激。提前谢谢。

以下是我的尝试：

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

代码中的一些内容并没有多大意义。首先，你尝试迭代$totalreceivers两次，一个循环嵌套在另一个循环中。我怀疑这是你想要的，所以你应该摆脱其中一个。并且您的第一个循环有一个错误的表达式：要在第一个$totalreceivers循环中迭代for，您需要让您的测试表达式与数组中的元素数量相对而不是数组本身（可以使用count（））：for ($i = 0; $i < count($totalreceivers); $i++)。

其次，每次在循环中调用$status时，您都会重置status()的值。要添加，请使用+=运算符：$status += status($receivers[$i]);

第三，你在{（1}}的status（）函数中做了同样的事情。重置它$rowservice循环的每次迭代。设置一次，或者总结一下。

Answer 2

乍一看，看起来你只是在每次迭代时覆盖“$ status”。在循环开始之前，将$ status设置为空数组，然后在每次迭代时添加到它。例如：

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

Answer 3

您可以让MySQL为您完成更多工作，从而简化此任务。

你有一个数组$receivers，可能包含订阅者（某些人的接收者）的id。（我可以互换使用接收器和用户。）

status()函数从数据库中检索value为空的每个接收者的subscription_end_date。我将假设每个订阅者只有一行，因为您只通过变量$rowservice返回最后一个结果。

您的代码中不清楚您是否需要计数除{0}以外的value的接收器，或者您想要所有非零值的总和。那么问题是：

您想知道有多少订阅者拥有非零值吗？或者，
您想知道具有非零值的订阅者的所有值的总和吗？

幸运的是，这些都很容易找到：

有多少接收器具有非零值？

$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";

所有接收者值的总和是多少？

$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 4

我将尝试在下面的代码中概述一些可能的问题：

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*/

php问题在循环中有值的总和

4 个答案: