可能重复：
内部while循环不起作用
这是我项目网页中的一段代码。在这里，我想显示用户选择的类别，然后想显示属于类别的主题。在那里，用户可能有超过 1 个类别，没问题我可以在我的第一个 while 循环中打印所有这些类别……但问题是当我尝试打印主题时，结果只有一行……还有更多主题在每个类别中。谁能告诉我发生了什么？
这是我的代码....注意：两个查询都正常工作..我尝试了那些用户 mysql 客户端程序。
<?php
require_once ('../../includes/config.inc.php');
require_once( MYSQL1 );
$outQuery = "SELECT institute_category.category_id, category_name
FROM institute_category
INNER JOIN category ON institute_category.category_id = category.category_id
WHERE institute_category.institute_id = $instituteId";
$outResult = mysqli_query( $dbc, $outQuery);
while ( $outRow = mysqli_fetch_array ( $outResult, MYSQLI_ASSOC) ) {
$categoryId = $outRow['category_id'];
$category = $outRow['category_name'];
echo '<fieldset class="alt">
<legend><span>Category : <em style="color: red;">' . $category . '</em></span></legend>';
$innerQuery = "SELECT category_subject.category_id, category_subject.subject_id, subjects
FROM category_subject
INNER JOIN category ON category_subject.category_id = category.category_id
INNER JOIN subject ON category_subject.subject_id = subject.subject_id
WHERE category_subject.category_id = $categoryId";
$innerResult = mysqli_query( $dbc, $innerQuery);
$c = $i = 0;
echo '<table class="form_table" ><tr>';
while($innerRow = mysqli_fetch_array( $innerResult, MYSQLI_ASSOC )){
// if remainder is zero after 2 iterations (for 2 columns) and when $c > 0, end row and start a new row:
if( ($c % 2) == 0 && $c != 0){
echo "</tr><tr>";
}
echo '<td width="50%"><input type="checkbox" name="subject[]" value="' . $innerRow['category_id'] . ":" . $category . ":" . $innerRow['subject_id'] . ":". $innerRow['subjects'] . '" /> ' . $innerRow['subjects'] . '</td>' . "\n";
$c++;
} // while..
// in case you need to fill a last empty cell:
if ( ( $i % 2 ) != 0 ){
// str_repeat() will be handy when you want more than 2 columns
echo str_repeat( "<td> </td>", ( 2 - ( $i % 2 ) ) );
}
echo "</tr></table>";
}
echo '</fieldset>';
?>
这是我的 HTML
good<fieldset class='alt'>
<legend><span>Category : <em style='color: red;'>grade 1 - 4</em></span></legend>
<table class='form_table'><tr>
<tr>
<td width='50%'><input type='checkbox' name='subject[]' value='2:grade 1 - 4:2:Art' /> Art</td>
<td width='50%'><input type='checkbox' name='subject[]' value='2:grade 1 - 4:3:Art & Craft' /> Art & Craft</td>
</tr>
<tr>
<td width='50%'><input type='checkbox' name='subject[]' value='2:grade 1 - 4:4:Bialogy' /> Bialogy</td>
<td width='50%'><input type='checkbox' name='subject[]' value='2:grade 1 - 4:5:Buddhism' /> Buddhism</td>
</tr>
</table>
<fieldset class='alt'>
<legend><span>Category : <em style='color: red;'>grade 5 (scholarship exam)</em></span></legend>
<table class='form_table'><tr>
<tr>
<td width='50%'><input type='checkbox' name='subject[]' value='3:grade 5 (scholarship exam):1:Agro & Food Technology' /> Agro & Food Technology</td>
<td width='50%'><input type='checkbox' name='subject[]' value='3:grade 5 (scholarship exam):2:Art' /> Art</td>
</tr>
<tr>
<td width='50%'><input type='checkbox' name='subject[]' value='3:grade 5 (scholarship exam):3:Art & Craft' /> Art & Craft</td>
<td width='50%'><input type='checkbox' name='subject[]' value='3:grade 5 (scholarship exam):4:Bialogy' /> Bialogy</td>
</tr>
</table>
<fieldset class='alt'>
<legend><span>Category : <em style='color: red;'>grade 6 - 10</em></span></legend>
<table class='form_table'><tr>
<tr>
<td width='50%'><input type='checkbox' name='subject[]' value='4:grade 6 - 10:2:Art' /> Art</td>
<td width='50%'><input type='checkbox' name='subject[]' value='4:grade 6 - 10:3:Art & Craft' /> Art & Craft</td>
</tr>
<tr>
<td width='50%'><input type='checkbox' name='subject[]' value='4:grade 6 - 10:4:Bialogy' /> Bialogy</td>
<td width='50%'><input type='checkbox' name='subject[]' value='4:grade 6 - 10:5:Buddhism' /> Buddhism</td>
</tr>
</table>
</fieldset>
任何意见都非常感谢..
谢谢你