How to insert multiple rows by select or checkbox - php

Question

I've got a problem with inserting multiple row to one table.
I've got a 3 tables:
1. student with id_student
2. ankieta with id_ankieta
3. student_ankieta with id_student and id_ankieta
I want to choose students from database using select or checkbox and choose one id_ankieta. After confirming, there are rows created in table (student_ankieta).
Now I can choose students but when I confirm, only one student gets added to the database.
Can anyone help me corect the code?
<?php
echo'<form method="post" action="student_ankieta.php">
<div class="box" style="margin:0 auto; top:0px;">
<h1>Student - ankieta:</h1>
<label>
<span><br/>Ankieta:</span>
</label>
<select class="wpis" name="id_ankieta">
<option>wybierz ankiete</option>';
$query = "SELECT * FROM ankieta";
$result = mysql_query($query);
while ($row = mysql_fetch_array($result))
{
echo '<option value="'.$row['id_ankieta'].'">' . $row{'rok_akademicki'}.' '. $row{'semestr_akademicki'}.' '.$row{'active_ankieta'} .'</option>';
}
echo '
</select>';
$query = "SELECT * FROM student";
$result = mysql_query($query);
echo'
<label>
<span><br/>Wybierz stundentów:</span>
</label>
<select multiple="multiple" name="id_student[]" size="10">';
while ($row = mysql_fetch_assoc($result))
{
echo '<option class="wpis" value="'.$row['id_student'].'" />'.$row{'pesel'}.' '. $row{'nazwisko'}.' '.$row{'imie'} .'</option>';
}
echo'<br/><input class="button" type="submit" value="Dodaj ankiete" name="dodaja">';
if(isset($_POST['dodaja']))
{
$id_ankieta = $_POST['id_ankieta'];
if(empty($_POST['id_ankieta']))
{
echo '<p style="margin-top:10px; font-size:75%; font-family: Calibri; color: red; text-align:center;">Musisz wypełnić wszystkie pola.</p>';
}
else
{
$id_student = $_POST['id_student'];
for ($i = 0; $i < count($id_student); $i++)
{
$id_student = $id_student[$i];
mysql_query("INSERT INTO student_ankieta (id_student, id_ankieta) VALUES ('" . $id_student . "','$id_ankieta')");
}
}
}
echo'</div></form>';?>

Answer 1

Put all students in to an array with the key = id_student
$query = "SELECT * FROM ankieta";
$result = mysql_query($query);
while ($row = mysql_fetch_assoc($result)) {
students[$row['id_student']] = array($row['pesel'],$row['nazwisko'],$row['imie'];
}
If the form was posted the confirm will = 1 (from hidden input)
When first enter script "confirm will = 0
When zero, display all student with a check box with a name which includes the id_student in the format of n-i_student.
if intval($_POST['confirm']) = 0){
echo '<form action = "confirm.php" method="post"><input type="hidden" name="confirm" value="1"/><table>';
foreach ($students as $id => val){
echo "<tr><td><input type=\"checkbox\" name=\"n-$id\" value=\"1\" /> Select </div></td>$val[0]<td>$val[0]</td><td>$val[1]</td><td>$val[2]</td></tr>";
}
echo '</table></form>';
}
When confirm = 1
The checkboxes that were checked are inserted.
Check each post value for a key the starts with "n-"
get the rest of the key value after the n- for the id_student value.
Still 1 Major Problem, I do not know where to get the $id_ankieta'
And match it with the id_student.
I left that value as $val[???]
elseif intval($_POST['confirm']) = 1){
foreach ($_POST as $k =>$val){
if (inval($val) == 1 && substr($k,0,2) == 'n-'){
$id = substr($k,2);
$sql = mysql_query("INSERT INTO student_ankieta (id_student, id_ankieta) VALUES ('$id','" . $students[$id][$val[???]] . "')");
}
}
}