Question

我有一个MySQL查询，它在phpmyadmin中执行时会返回正确的结果，但有人知道如何使这更加简化（更简单）以及将$trackNumber变量附加到$info['trackName']内PHP while循环？

$data = mysql_query(" SELECT 
/* Track 1 */
  ( SELECT 
    tr.trackName
        FROM league l 
        INNER JOIN tracks tr ON tr.trackID = l.track1
        WHERE l.leagueID = 1
    ) AS trackName1

/* Track 2 */
, ( SELECT 
    tr.trackName
        FROM league l 
        INNER JOIN tracks tr ON tr.trackID = l.track2
        WHERE l.leagueID = 1
    ) AS trackName2

/* Track 3 */
, ( SELECT 
    tr.trackName
        FROM league l 
        INNER JOIN tracks tr ON tr.trackID = l.track3
        WHERE l.leagueID = 1
    ) AS trackName3

/* Track 4 */
, ( SELECT 
    tr.trackName
        FROM league l 
        INNER JOIN tracks tr ON tr.trackID = l.track4
        WHERE l.leagueID = 1
    ) AS trackName4

/* Track 5 */
, ( SELECT 
    tr.trackName
        FROM league l 
        INNER JOIN tracks tr ON tr.trackID = l.track5
        WHERE l.leagueID = 1
    ) AS trackName5

/* Track 6 */
, ( SELECT 
        tr.trackName
        FROM league l 
        INNER JOIN tracks tr ON tr.trackID = l.track6
        WHERE l.leagueID = 1
    ) AS trackName6

/* Track 7 */
, ( SELECT 
        tr.trackName
        FROM league l 
        INNER JOIN tracks tr ON tr.trackID = l.track7
        WHERE l.leagueID = 1
    ) AS trackName7

/* Track 8 */
, ( SELECT 
        tr.trackName
        FROM league l 
        INNER JOIN tracks tr ON tr.trackID = l.track8
        WHERE l.leagueID = 1
    ) AS trackName8

/* Track 9 */
, ( SELECT 
        tr.trackName
        FROM league l 
        INNER JOIN tracks tr ON tr.trackID = l.track9
        WHERE l.leagueID = 1
    ) AS trackName9

/* Track 10 */
, ( SELECT 
        tr.trackName
        FROM league l 
        INNER JOIN tracks tr ON tr.trackID = l.track10
        WHERE l.leagueID = 1
    ) AS trackName10

FROM league 
WHERE leagueID = 1 ");

$trackNumber = 1;

while($info = mysql_fetch_assoc( $data )) {

echo "<div class=\"col-lg-3\" align=\"center\">\n";
echo " <h5> <hr/>Track " . $trackNumber  . "<hr/></h5><p>" . $info['trackName['$trackNumber']'] . "</p>\n";
echo " </div>\n";

$trackNumber++;

}

Answer 1

您的查询只返回一行，您不应该在循环中调用mysql_fetch_assoc()。要访问特定轨道号的列，您需要使用字符串连接来生成数组键：$info['trackName' . $trackNumber]

$info = mysql_fetch_assoc($data);

for ($trackNumber = 1; $trackNumber <= 10; $tracknumber++) {
    echo "<div class=\"col-lg-3\" align=\"center\">\n";
    echo " <h5> <hr/>Track " . $trackNumber  . "<hr/></h5><p>" . $info['trackName' . $trackNumber] . "</p>\n";
    echo " </div>\n";
}

Answer 2

您应该能够直接从每个子查询中的[曲目]中进行选择 - 对[联盟]的引用似乎是不必要的，因为您已经在查询的正文中得到了这些内容。

因此，您的第一个子查询将成为：

( SELECT 
    tr.trackName
    FROM tracks tr
    WHERE tr.trackID = l.track1
) AS trackName1

Answer 3

PHP PDO：

$conn = new PDO("connectionString", $yourUsername, $yourPassword);
$std = $conn->prepare(' SELECT...(your query)');
$std->execute();
$tracks = $std->fetchAll(PDO::FETCH_OBJ);

var_dump($tracks);

foreach($tracks as $track)
{
?>
<div class=\"col-lg-3\" align=\"center\">
<h5>Number: <?= $track->trackNumber  ?></h5>
<p>Name: <?= $track->trackName ?></p>
</div>
<?php
}

使用const FETCH_OBJ将返回每一行作为表列名称的表示作为属性。你可以使用FETCH_ASSOC但是会返回一个关联数组。对我来说，这将是更清晰，更优雅的方法，而不是mysql函数。

MySQL循环并将变量分配给PHP变量

3 个答案: