不知道如何从 MySql 查询中获取数据

Question

我之前问了一个关于如何进行此查询的问题，并得到了很好的回应。 不幸的是，它比我通常运行的查询要高级一些，所以我无法弄清楚如何检索结果并将它们显示在我的 web 页面上。 这是原始问题原始问题的链接

     <?php

// Associative array
$result = $db->query("SELECT Name,
       COALESCE(AVG(CASE WHEN mth = 1 THEN PTS END), 0) AS Jan,
       COALESCE(AVG(CASE WHEN mth = 2 THEN PTS END), 0) AS Feb,
       COALESCE(AVG(CASE WHEN mth = 3 THEN PTS END), 0) AS Mar,
       COALESCE(AVG(CASE WHEN mth = 4 THEN PTS END), 0) AS Apr,
       COALESCE(AVG(CASE WHEN mth = 5 THEN PTS END), 0) AS May,
       COALESCE(AVG(CASE WHEN mth = 6 THEN PTS END), 0) AS Jun,
       COALESCE(AVG(CASE WHEN mth = 7 THEN PTS END), 0) AS Jul,
       COALESCE(AVG(CASE WHEN mth = 8 THEN PTS END), 0) AS Aug,
       COALESCE(AVG(CASE WHEN mth = 9 THEN PTS END), 0) AS Sep,
       COALESCE(AVG(CASE WHEN mth = 10 THEN PTS END), 0) AS Oct,
       COALESCE(AVG(CASE WHEN mth = 11 THEN PTS END), 0) AS Nov,
       COALESCE(AVG(CASE WHEN mth = 12 THEN PTS END), 0) AS Dec,
       AVG(PTS) AS AVG
FROM (
  SELECT Name, `Points Pass` AS PTS, MONTH(STR_TO_DATE(`OS Date`, '%a %b %e %H:%i:%s %Y')) AS mth
  FROM data
) d
GROUP BY Name");


while($row = mysqli_fetch_array($result)) {

            ?>

         <tr>
                <td><?php echo $row['Name']; ?></td>
                <td class = "gScore-<?php echo $row['Jan']; ?>"><?php echo $row['Jan']; ?></td>
                <td class = "gScore-<?php echo $row['Feb']; ?>"><?php echo $row['Feb']; ?></td>
                <td class = "gScore-<?php echo $row['Mar']; ?>"><?php echo $row['Mar']; ?></td>
                <td class = "gScore-<?php echo $row['Apr']; ?>"><?php echo $row['Apr']; ?></td>
                <td class = "gScore-<?php echo $row['May']; ?>"><?php echo $row['May']; ?></td>
                <td class = "gScore-<?php echo $row['Jun']; ?>"><?php echo $row['Jun']; ?></td>
                <td class = "gScore-<?php echo $row['Jul']; ?>"><?php echo $row['Jul']; ?></td>
                <td class = "gScore-<?php echo $row['Aug']; ?>"><?php echo $row['Aug']; ?></td>
                <td class = "gScore-<?php echo $row['Sep']; ?>"><?php echo $row['Sep']; ?></td>
                <td class = "gScore-<?php echo $row['Oct']; ?>"><?php echo $row['Oct']; ?></td>
                <td class = "gScore-<?php echo $row['Nov']; ?>"><?php echo $row['Nov']; ?></td>
                <td class = "gScore-<?php echo $row['Dec']; ?>"><?php echo $row['Dec']; ?></td>
                <td><?php echo $row['AVG']; ?></td>
            </tr>
        <?php   


}
if (!$result) { echo $db->error; }

Answer 1

你有几个问题：

1. $row的索引需要用引号括起来，例如$row['name']否则你会得到很多“未定义的常量”警告；
2. $row['Jan']是检索每月数据的正确方法，您需要为其他每个月复制它；
3. 用$row['AVG']替换$avgGrade
4. 我不确定你想要达到什么目的

<td class = "gScore-<?php echo $row[Jan]; ?>"></td>

你真的想要吗

<td class = "gScore"><?php echo $row[Jan]; ?></td>

5. 您需要在查询中添加-- repeat for May to November行，即

    $result = $db->query("SELECT name,
       COALESCE(AVG(CASE WHEN mth = 1 THEN PTS END), 0) AS Jan,
       COALESCE(AVG(CASE WHEN mth = 2 THEN PTS END), 0) AS Feb,
       COALESCE(AVG(CASE WHEN mth = 3 THEN PTS END), 0) AS Mar,
       COALESCE(AVG(CASE WHEN mth = 4 THEN PTS END), 0) AS Apr,
       COALESCE(AVG(CASE WHEN mth = 5 THEN PTS END), 0) AS May,
       COALESCE(AVG(CASE WHEN mth = 6 THEN PTS END), 0) AS Jun,
       COALESCE(AVG(CASE WHEN mth = 7 THEN PTS END), 0) AS Jul,
       COALESCE(AVG(CASE WHEN mth = 8 THEN PTS END), 0) AS Aug,
       COALESCE(AVG(CASE WHEN mth = 9 THEN PTS END), 0) AS Sep,
       COALESCE(AVG(CASE WHEN mth = 10 THEN PTS END), 0) AS Oct,
       COALESCE(AVG(CASE WHEN mth = 11 THEN PTS END), 0) AS Nov,
       COALESCE(AVG(CASE WHEN mth = 12 THEN PTS END), 0) AS `Dec`,
       AVG(PTS) AS AVG
   FROM (
   SELECT name, PTS AS PTS, MONTH(STR_TO_DATE(DATE, '%a %b %e %H:%i:%s %Y')) AS mth
   FROM data
    ) d
    GROUP BY name");