これはあなたのために働くはずです。これにより、各生徒に一意の値が割り当てられます。このpresent値は、ポストバックでチェックされ、設定されている場合は、クリーンアップされて、出席している生徒の記録を更新するために使用されます。
また、PHPでエコーされたHTMLをHTMLに抽出し、フォームをテーブルの外に移動しました（一部のブラウザーで問題が発生する可能性があります）。
<?php
// Update present values
if (isset($_POST['submit']))
{
// Get a list of student ids to check
$idsResult = mysql_query("SELECT student_id from students");
while($idRow = mysql_fetch_array($idsResult))
{
// if the textbox for this student is set
if(isset($_POST['present'.$idRow['student_id']]) && !empty($_POST['present'.$idRow['student_id']]))
{
// Clean the user input, then escape and update the database
$cleanedPresent = htmlspecialchars(strip_tags($_POST['present'.$idRow['student_id']]));
$sql = "UPDATE course_attendance SET present='".mysql_real_escape_string($present)."' WHERE course_id='101' AND week_id='2' AND student_id=".$idRow['student_id'];
$result = mysql_query($sql);
if($result){
echo "Successfully logged the attendance for ID ".$idRow['student_id'];
}
else {
echo "ERROR updating on ID ".$idRow['student_id'];
}
}
}
}
$test3= "SELECT * FROM course_attendance, students, courses, attendance WHERE course_attendance.course_id=courses.course_id AND course_attendance.week_id=attendance.week_number_id AND course_attendance.student_id= students.student_id AND courses.course_id='101' AND attendance.week_number_id='2' ";
$result = mysql_query($test3) or die(mysql_error());
?>
<form name='Biology_lecture11.php' method='post'>
</br>
<table border='1' align='center'>
<tr>
<th><strong>Student ID</strong></th>
<th><strong>First Name </strong></th>
<th><strong>Last Name</strong></th>
<th><strong>Present</strong></th>
</tr>
<?php
while($rows=mysql_fetch_array($result)){
echo "<tr><td width='100' align='center'>" .$rows['student_id'].
"</td><td width='120' align='center'>" .$rows['fname'].
"</td><td width='120' align='center'>" .$rows['lname'].
"</td><td><input type='text' name='present".$rows['student_id']."' value=" .$rows['present'] . ">";
}
?>
</table>
<input type='submit' name='Submit' value='Submit'>
</form>
代替（より良い）方法：現在価値を単純な0/1またはtrue / falseに設定できる場合は、各生徒のチェックボックスを使用する方が簡単です。ポストバックでは、出席している学生を示す各チェックボックスをオンにして値の配列を取得し、1つのクエリでデータベーステーブルを更新できます。また、悪意のあるテキスト入力を防ぎます。
代替コード：
<?php
// Update present values
if (isset($_POST['submit']))
{
// Get a list of student ids to check
$idsResult = mysql_query("SELECT student_id from students");
$presentIds = array();
$absentIds = array();
while($idRow = mysql_fetch_array($idsResult))
{
// If the student's checkbox is checked, add it to the presentIds array.
if(isset($_POST['present'.$idRow['student_id']]))
{
$presentIds[] = $idRow['student_id'];
}
else
{
$absentIds[] = $idRow['student_id'];
}
}
// Convert array to string for query
$idsAsString = implode(",", $presentIds);
// You can set present to whatever you want. I used 1.
$sql = "UPDATE course_attendance SET present='1' WHERE course_id='101' AND week_id='2' AND student_id IN (".$idsAsString.")";
$result = mysql_query($sql);
if($result){
echo "Successfully logged the attendance for IDs ".$idsAsString;
}
else {
echo "ERROR updating on IDs ".$idsAsString;
}
// OPTIONAL: Mark absent students as '0' or whatever other value you want
$absentIdsAsString = implode(",", $absentIds);
// You can set present to whatever you want. I used 1.
$absentQuery = "UPDATE course_attendance SET present='0' WHERE course_id='101' AND week_id='2' AND student_id IN (".$absentIdsAsString.")";
$absentResult = mysql_query($absentQuery);
if($absentResult){
echo "Successfully logged absence for IDs ".$absentIdsAsString;
}
else {
echo "ERROR updating absence on IDs ".$absentIdsAsString;
}
}
$test3= "SELECT * FROM course_attendance, students, courses, attendance WHERE course_attendance.course_id=courses.course_id AND course_attendance.week_id=attendance.week_number_id AND course_attendance.student_id= students.student_id AND courses.course_id='101' AND attendance.week_number_id='2' ";
$result = mysql_query($test3) or die(mysql_error());
?>
<form name='Biology_lecture11.php' method='post'>
</br>
<table border='1' align='center'>
<tr>
<th><strong>Student ID</strong></th>
<th><strong>First Name </strong></th>
<th><strong>Last Name</strong></th>
<th><strong>Present</strong></th>
</tr>
<?php
while($rows=mysql_fetch_array($result)){
echo "<tr><td width='100' align='center'>" .$rows['student_id'].
"</td><td width='120' align='center'>" .$rows['fname'].
"</td><td width='120' align='center'>" .$rows['lname'].
"</td><td><input type='checkbox' name='present".$rows['student_id']."' ";
// NOTE: REPLACE 1 with whatever value you store in the database for being present.
// I used 1 since the update at the top of the code uses 0 and 1.
if($rows['present']=='1')
{
echo "checked='checked' ";
}
// With a checkbox, you don't need to assign it a value.
echo "value=" .$rows['present'];
echo ">";
}
?>
</table>
<input type='submit' name='Submit' value='Submit'>
</form>