Checkbox help

[Valord]

Hey all.

I am having a brain freeze here. I a table that has several entries all pulled from a mysql db. Each entry has a checkbox. I am trying to write some code so that when a uses checks one/several checkboxes and clicks update, the records will be deleted from the db.

Each checkbox is named a sequential number. I am having trouble figuring out how to send the names and if they are checked or not to a php script. Can anyone help with this?

Thanks

Todd

[Shrike]

Make the sequential number in the checkbox equal to the id of the row in the database. Then set the name of all the checkboxes to be "somename[]" (the [] brackets being the key part). Then you can do

foreach($_POST['somename'] as $value){
  $sql = "DELETE FROM table WHERE id = $value";
  mysql_query($sql);
}

[Valord]

Thanks for the reply. I think I see what you are saying but I have a question. The sequential number is currently the name of the checkbox. Would I have to change that?

[Shrike]

Yes it would need to relate to the id field of the database row, to allow the SQL statement a few lines down.

I should point out that this opens up a security hole, in that changing the numbers in the checkboxes would allow deletion of any row. You'd need something extra to make sure a user is only deleting rows which they are allowed to.

[Valord]

Thanks again. Just one more question (sorry, being stupid this morning). What then in the checkbox would be the sequential number? Thanks

[Shrike]

The id of the database row - whatever piece of data uniquely identifies that row. If the id is a text string, you'll need to quote the last parameter in the SQL query.

[Valord]

I'm sorry, I meant in the actual form. Would you set the value part of the checkbox equal to the identifier in the db?

[Shrike]

Yes, and the name of every checkbox as "somename[]"

[Valord]

Ok thanks. You have been a huge help. My brainfreeze is over hehe

[Valord]

ok, I still seem to be having some problems with this. The php script (update.php) gets the correct id number but for some reason it doesn't delete the row from the database. I made an auto increment field in the db and use that to fill the value portion of the checkbox. I am posting code for both the script and for the form. If anyone has any ideas it would be very helpful. Thanks

Form

$result = mysql_query("SELECT * FROM main" ,$connection);
while($myrow = mysql_fetch_array($result)){
$value = $myrow['index'];
echo "<tr><td width=10% align=center><input type=checkbox name=remove[] value=$value> . . .

Update.php

foreach($_POST['remove'] as $value){
$sql = "DELETE FROM main WHERE index = $value";
mysql_query($sql);

[Hiccup]

Originally posted by Valord
<input type=checkbox name=remove[] value=$value>

Replace that line with:

<input type=hidden name=id[$count] value=$id_from_your_table>
<input type=checkbox name=remove[$count]>

You'll need to have a variable set as $count=0; outside the loop where you're printing out the checkboxes and other info.

Originally posted by Valord
Update.php

foreach($_POST['remove'] as $value){
$sql = "DELETE FROM main WHERE index = $value";
mysql_query($sql);

Replace that foreach loop with a for loop instead:

for($i=0;$i<=$count;$i++){
 if($remove[$i] == "on"){
  $sql = "DELETE FROM main WHERE id = 'id[$i]'";
  mysql_query($sql);
 } 
}

That's how I handle these situations, my syntax may be off, but give it a shot!

[Valord]

Thanks for the reply. I'll give it a shot.

[Valord]

ok, I tried that but it doesn't look like the php script ever gets the value of $count. It doesn't throw up an error, but the row is still not deleted from the db 🙁

[laserlight]

Actually, the foreach loop is correct, since any checkboxes that are not checked will not have their values sent.

The problem lies with the implementation.
You have to consider security.

But first, you must determine how you plan to present the id of a given row.
Without this, you cant determine how the foreach loop will work.

[Valord]

I figured the foreach loop was working correctly since the correct value is getting passed.

I understand that I have to consider security, but right now I am just trying to figure out why the row isn't being removed from the db. I am not sure I understand what you mean by present the id.

[laserlight]

That's the exact point.

Take for example:

<input type="checkbox" name="delete[]" value="12">

Now say 12 is the id of the particular row.
Then we will use:

foreach ($_POST['delete'] as $del) {
	mysql_query("DELETE FROM tablename WHERE id='$del'")
		OR die(mysql_error()); //for debugging
}

If we use
<input type="checkbox" name="delete[12]" value="1">

then we will use:

foreach ($_POST['delete'] as $del => $value) {
	mysql_query("DELETE FROM tablename WHERE id='$del'")
		OR die(mysql_error()); //for debugging
}