fetch row data and update textarea to insert in mysql - php

Question

I have two column name varchar and area text
name area
abc 12a
dfg test
Now I want to update each of them from my page where I input some text to the textarea fetched from tow rows.
<?
if(isset($_POST['submit'])) {
$i = 0;
foreach($_POST['txt'] as $textarea) {
#$val[$i] = $val[$i].$textarea;
$i++;
}
foreach($val as $value){
$q= mysql_query("UPDATE table_name SET name = '$value' WHERE `area` = '??'");
echo "Success"; }
$sql="select * from table_name";
$res=mysql_query($sql);
?>
<form name="form1" method="post" action="<?php echo $_SERVER['PHP_SELF'];?>">
<table border="1">
<thead>
<tr>
<th>NAME</th>
<th>AREA</th>
</tr>
<?php while($row=mysql_fetch_assoc($res))
{
?>
<tr>
<td><?php echo $row['name']; ?></td>
<td><textarea rows="4" cols="40" name="txt[]"><?php echo $row['area']; ?> </textarea><br/>
</td>
</tr>
<tr>
</tr>
<?php } ?>
<tr>
<td><input type="submit" name="submit" id="submit" value="Update" /></td>
</tr>
</table>
</form>
I am getting the name but could not update/insert it in area for that name. How do I accomplish this?

Answer 1

the most easy fix is to take a hidden input field and pass the $row['name']
<input type="hidden" name="name[]" value="<?php echo $row['name'];?>"/>
then
if(isset($_POST['submit'])) {
$area=$_POST['txt'];
$name=$_POST['name'];
$count=count($area);
for($i=0; $i<$count; $i++)
{
if(mysql_query("UPDATE table_name SET area = '".$area[$i]."' WHERE `name` = '".$name[$i]."'"))
{
NB:-if u have a id column then take hidden input field with $row['id'] and do the same

Answer 2

You can embed actual keys in PHP's array-naming hack:
<textarea name="txt[foo]">...</textarea>
<textarea name="txt[bar]">...</textarea>
Which allows you to directly associate a particular form field with the value it represents in the database. In your case:
while($row = fetch_from_db()) {
output: <texarea name="txt[$row[id]]">$row[area]</textarea>
}
And then, after submitting:
foreach($_POST['txt'] as $key => $value) {
update database : UPDATE ... SET area=value WHERE id=$key
}
Note that your code is vulnerable to sql injection attacks.