循环通过数据库[关闭]

Question

我想遍历我的玩家表并为每个玩家运行以下代码，我可以使用以下代码还是使用“else”错误选项，我需要它运行所有 if 语句以查看是否有匹配项，然后根据需要更新数据库。基本上我需要知道的是我是否走在正确的轨道上，或者我应该考虑使用 do、while、foreach、else、elseif、switch 等。下面的代码只是示例。只是试图理解理论。

<?php
$getresult = $conn->query('SELECT id FROM users');
 while ($getrow = mysqli_fetch_array($getresult); {
    $player = $getrow['id'];

$result = $conn->query("SELECT * FROM scores WHERE player_id='$playerId' ORDER by points ASC");
$row = $result->fetch_array();
$row_count = mysqli_num_rows($result);

if ($row_count...) {


}else{

    if ($row_count...) {

    }else{

         if () {

         }else{
  }
//SQL update statement would go here..
}

Answer 1

您可以执行SELECT id FROM playersTable 之类的操作，然后在while 循环中获取 player_id，然后将其余代码移动到该循环中。那是你要找的还是我错过了什么？

// $player = $_SESSION['id'];
$playersResult = $conn->query('SELECT id FROM playersTable');
while ($playersRow = mysqli_fetch_array($playersResult); {
    $playerId = $playersRow['id'];

    $result = $conn->query("SELECT * FROM scores WHERE player_id='$playerId' ORDER by points ASC");
    $row = $result->fetch_array();
    $row_count = mysqli_num_rows($result);

    if ($row_count >= 20) { // checks that at least 10 rows available
        $result = $conn->query("SELECT points FROM scores WHERE player_id='$playerId' ORDER by points ASC LIMIT 10"); // select 10 lowest points
        while ($row = mysqli_fetch_array($result)) {
            $total = array($row['points']);
            $sum = array_sum($total);
            echo $sum;
        }
    }
    else if ($row_count>=10) { // checks that at least 10 rows available
        $result = $conn->query("SELECT points FROM scores WHERE player_id='$playerId' ORDER by points ASC LIMIT 5"); // select 5 lowest points
        while ($row = mysqli_fetch_array($result)) {
            $total = array($row['points']);
            $sum = array_sum($total);
            echo $sum;
        } 
    }

    //SQL update statement would go here..
}

您可能还想检查您的求和逻辑，但没有看到您的表结构，我认为 array_sum 不会做您想做的事情。您可以使用SQL SUM() 为您进行计算。