Unique radio name in php while loop - php

Question

Well, I've following Php code which generate a table with radio button so that user can select only one radio button in EVERY row. But to select only one radio button in Every row it's must be a unique name in EVERY row, Right ? But I can't get any idea how do i set a unique name in while loop. Can you guys give me any idea or solutions ?
Php code:
$action = htmlspecialchars($_SERVER['PHP_SELF'])."?class=$class_from";
echo "<form method='post' action='$action' name='attendence'/>";
echo "<table width='100%' cellpadding='0' cellspacing='0' border='0'>";
echo "<tr>";
echo "<td class='tdhead' valign='top' width='200'><b>Student Name</b></td>";
echo "<td class='tdhead' valign='top' width='250'><b>Roll No</b>
</td>";
echo "<td class='tdhead' valign='top' width='250'><b>Class Name</b>
</td>";
echo "<td class='tdhead' valign='top' width='200'><b>Present / Not present</b>
</td>";
echo "<td class='tdhead' valign='top' width='200'>Check All <input type= 'checkbox'
onclick='checkAll(this)' /></td>";
echo "</tr>";
while($res2 = mysql_fetch_array($sql2))
{
$sname = inputvalid($res2['sname']);
$roll = inputvalid($res2['roll']);
$class = inputvalid($res2['class']);
echo "<tr>";
echo "<td class='tdhead2' valign='top'>$sname</td>";
echo "<td class='tdhead2' valign='top'>$roll</td>";
echo "<td class='tdhead2' valign='top'>$class</td>";
echo "<td class='tdhead2' valign='top'>
<input type='radio' name='ch[]' value='1' /> <input type='radio' name='ch[]'
value='1' />
</td>";
echo "<td class='tdhead2' valign='top'> </td>";
echo "</tr>";
}
echo "<tr>";
echo "<td class='tdhead2'> </td>";
echo "<td class='tdhead2'> </td>";
echo "<td class='tdhead2'> </td>";
echo "<td class='tdhead2'> </td>";
echo "<td class='tdhead2'><input type='submit' value='Record' name='Submit'
class='submit' /></td>";
echo "</tr>";
echo "</table>";
echo "</form>";
Thanks for your help.
Update:
echo "<td class='tdhead2' valign='top'>";
echo '<input type="radio" name="ch'.$counter++.'[]" value="1">';
echo " ";
echo '<input type="radio" name="ch'.$counter.'[]" value="0">';
echo "</td>";

Answer 1

you can set a variable counter:
$counter = 1;
while($res2 = mysql_fetch_array($sql2)){
echo '<input type="radio" name="ch'.$counter++.'[]" value="'.$counter++.'">';
}

Answer 2

Instead of making the name just ch[] you can make the name ch[SOME_UNIQUE_VALUE] for each row. Usually something like an id number is used. Perhaps $roll if that is unique to each student. That will also allow you to know which id the radio button pertains to. On form submit, you can foreach($_POST['ch'] as $id=>$value) and get the id out.
Edit:
Example code:
//start the counter variable
$counter = 1;
while($res2 = mysql_fetch_array($sql2))
{
$sname = inputvalid($res2['sname']);
$roll = inputvalid($res2['roll']);
$class = inputvalid($res2['class']);
echo "<tr>";
echo "<td class='tdhead2' valign='top'>$sname</td>";
echo "<td class='tdhead2' valign='top'>$roll</td>";
echo "<td class='tdhead2' valign='top'>$class</td>";
echo "<td class='tdhead2' valign='top'>";
//echo each radio with the counter for this row
echo "<input type='radio' name='ch_{$counter}[]' value='0' /> ";
echo "<input type='radio' name='ch_{$counter}[]' value='1' />";
echo "</td>";
echo "<td class='tdhead2' valign='top'> </td>";
echo "</tr>";
//add one to the counter
$counter++;
}
Please note, unless you do like I suggested above, you will not be able to know which student each radio group goes to. You can assume that the radio buttons on group row 1 belongs to the student in row 1, but you might not know which student is in row 1. Which is why I suggest you put a unique id that goes with each student with each radio button instead of a counter.

Answer 3

You can store a counter $count and increase it after each iteration. Or if you have some unique id from the database per row (for example the primary_key), you can use that instead.$id = $res['id']
Then concat that value to the name=ch".$id."...

Answer 4

you should use student name as an unique array and put that value in the name=""
and it will auto increment according to the name and you can only choose single option at single row.
try this :
<input type='radio' name='<?php echo $res2['sname'];?>' value='0' /> ";
<input type='radio' name='<?php echo $res2['sname'];?>' value='1' />";
this solutio will work.because it work's for me in an attendance system.