php - 选择多列时，脚本（while-loop）停止并且没有输出

Question

我想从 TABLE 中选择多个列，但是一旦 while 循环开始，脚本就无法工作。我的 php 和 html 代码是：

<table border="0">
include_once $_SERVER['DOCUMENT_ROOT'].'/include/db.inc.php' ;
$sql="select post_title,post_desc,post_date,course,semester,firstname,lastname 
      FROM wbut_forum_posts left join users on post_by = email
      ORDER BY post_id DESC LIMIT 25";
$result = mysqli_query($link,$sql );

if (!$result) {
    include_once "wall.html.php";
    echo'<tr><td align="center"> OOOOPPPPPSSS!!!SORRY,UNABLE TO DISPLAY LATEST 25 TOPICS</td></tr>';
    exit();
}

while ($row = mysqli_fetch_array($result)) {
    $titles[] = $row['post_title'];
    $descs[] = $row['post_desc'];
    $dates[] = $row['post_date'];
    $courses[] = $row['course'];
    $semesters[] = $row['semester'];
    $firstnames[] = $row['firstname'];
    $lastnames[] = $row['lastname'];
}

$cnt=0;
foreach ($titles as $x) {
    $title[$cnt]=$x;
    $cnt=$cnt+1;
}

$cnt=0;
foreach ($firstnames as $x) {
    $firstname[$cnt]=$x;
    $cnt=$cnt+1;
}

$cnt=0;
foreach ($lastnames as $x) {
    $lastname[$cnt]=$x;
    $cnt=$cnt+1;
}

$cnt=0;
foreach ($descs as $x) {
    $descs[$cnt]=$x;
    $cnt=$cnt+1;
}

$cnt=0;
foreach ($dates as $x) {
    $date[$cnt]=$x;
    $cnt=$cnt+1;
}

$cnt=0;
foreach ($courses as $x) {
    $courses[$cnt]=$x;
    $cnt=$cnt+1;
}

$cnt=0;
foreach ($semesters as $x) {
    $semester[$cnt]=$x;
    $cnt=$cnt+1;
}

echo'AFTER FOREACHES';
for ($i=0;$i<$cnt;$i=$i+1) {

    echo'<table border="0">';
        echo'<tr>';
            echo '<td align="left"><span class="style1">';
                echo $firstname[$i] . " " . $lastname[$i] ;
            echo '</span></td>';
            echo '<td align="center"  colspan="2">RELATED COURSE :';
                echo $course[$i];
                echo '&nbsp;&nbsp;&nbsp;&nbsp; RELATED SEMESTER:';
                echo $semester[$i];
            echo '</td>';
        echo '</tr>';
        echo '<tr>';
            echo '<td>&nbsp;</td>';
            echo'<td align="left"><span class="style3">';
                echo  $desc[$i];
            echo '</span></td>';
            echo'<td valign="baseline">';
                echo $date[$i];
            echo '</td>';
        echo '</tr>';
        echo'<tr>';
            echo '<td>&nbsp;</td>';
            echo '<td align="left" background="reply_bg.gif"><span class="style3">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;';
                echo 'echo the replies here';
                echo '</span>';
            echo '</td>';
            echo'<td>&nbsp;</td>';
        echo '</tr>';
        echo '<tr>';
            echo '<td>&nbsp;</td>';
            echo '<form action="reply.html.php" method="post"><td align="left" ><textarea rows="5" cols="40" name="reply" id="reply"></textarea>    </td><td valign="baseline"><input type="submit" name="asd" value="REPLY" /><input type="hidden" name="reply" value="reply" /></td></form>';
        echo '  </tr>';
        echo '</table>';        
    }
    echo' CLOSING MAIN FOR ';
?>
</table>

注1：不工作..我已经在不同的地方回响。我注意到它在 while 循环开始时完全停止

Answer 1

1. 变量之后$sql，在哪里$result？
2. $result = mysql_query($sql) **or die(mysql_error)** // to give the output error from MySQL if there is any
3. 在 之前while，使用var_dump($row)或print_r($row)。
4. 如果您遇到空白页或没有错误报告，error_reporting(E_ALL);请在脚本的开头使用。

编辑：对不起，您使用的是 MySQLi。使用$mysqli->error.

Answer 2

您的代码的第一行没有打开 PHP 标记。它应该是：

<table border="0"><?