任何人都可以帮我解决这个问题。为了显示来自 MySql 数据库的结果,我必须选择学校、班级、科目和考试。但是列出所有课程或所有考试并不是很实用,所以我想做另一个功能,当我在第一个选择框中选择一些学校时,它会在第二个选择框中只显示所选学校的课程。
我的代码是:
<div id="allselects">
<form action="viewing.php" method="post" name="filt">
<div class="multsarrange">
<h1 class="choosetext" >Chose Schools</h1>
<select class="multipleselect" name="schools[]" size="8" multiple="multiple" id="shkll">
<?php
$sql = "SELECT * FROM schools ";
$scc=mysql_query($sql);
while ($db_f = mysql_fetch_assoc($scc)) {
$schcd=$db_f['schoolcode'];
$schc=$db_f['schoolname'];
echo "<option value=$schcd >$schc</option>";
}
?>
</select>
</div>
<div class="multsarrange" id="clasaajax">
<h1 class="choosetext" >Chose an Classes</h1>
<select class="multipleselect" name="classes[]" size="8" multiple="multiple" ">
<?php
$c = "SELECT * FROM classes ";
$cl=mysql_query($c);
while ($db_f = mysql_fetch_assoc($cl)) {
$clsc=$db_f['schoolID'];
$claid=$db_f['classID'];
$clay=$db_f['year'];
$clanm=$db_f['className'];
$name=schoolidton($clsc)." ".$clay." ".$clanm;
echo "<option value=$claid >$name</option>";
}
?>
</select>
</div>
<div class="multsarrange">
<h1 class="choosetext" >Chose Subjects</h1>
<select class="multipleselect" name="subjects[]" size="8" multiple="multiple">
<?php
$sb = "SELECT * FROM subjects ";
$sbi=mysql_query($sb);
while ($db_f = mysql_fetch_assoc($sbi)) {
$sbnm=$db_f['subjectName'];
$sbid=$db_f['subjectID'];
echo "<option value=$sbid >$sbnm</option>";
}
?>
</select>
</div>
<div class="multsarrange">
<h1 class="choosetext" >Chose Exams</h1>
<select class="multipleselect" name="exams[]" size="8" multiple="multiple">
<?php
$e = "SELECT * FROM exams ";
$ex=mysql_query($e);
while ($db_f = mysql_fetch_assoc($ex)) {
$id=$db_f['examID'];
$sub=$db_f['subjectID'];
$desc=$db_f['description'];
$year=$db_f['year'];
$data=$db_f['data'];
$exnam=subidton($sub)." - ".$year." - ".$desc." - ".$data;
echo "<option value=$id >$exnam</option>";
}
?>
</select>
</div>
<div id="longsubmit">
</br></br>
<input name="submit" type="submit" value="View" />
</div>
</form>
</div>