Variable variables in a function! Bah! Humbug!

[beardo]

This is a piece of code that works:

$count_cl+=1;
    for ($i=1; $i<$count_cl; $i++) {

    if (${"delete_".$i} == "Delete") {
    $sql = "UPDATE country SET zone_id='0' WHERE country_id='${"country_id_".$i}'";
    $result = @mysql_query($sql,$connection) or die("Couldn't delete from zone.");
    }
}

This is the same piece of code put into a function:

FUNCTION CALL:

shippingupdatezone($zone_id,$count_cl, ${"delete_".$i}, ${"country_id_".$i});

FUNCTION:

function shippingupdatezone($zone_id,$count_cl, $delete, $countryID) {
    if (!$count_cl) { 
    header("location: .....BLAH");
    exit;
    }
    else {
    $count_cl+=1;
    for ($i=1; $i<$count_cl; $i++) {
        if ($delete == "Delete") {
        $sql = "UPDATE country SET zone_id='0' WHERE country_id='$countryID'";
        $result = @mysql_query($sql,$connection) or die("Couldn't delete from zone.");
        }
    }
    header("location: BLAH....&zone_id=$zone_id");
    exit;
    }

}

The second piece of code does not work and I do not understand why. Does anyone have any idea? I am new to functions and was informed that this was the way to handle my variable variables.

The part I do not understand (a part from the fact that this clearly does not work) is that at the point of the function call the $i var is not set.....

[TheJuice]

Well I see at least one problem:
In your function, the variable $connection is unknown from the function since you did not use a global variable.

So you have two choices: you pass it as a parameter, or you write this line inside your function:
GLOBAL $connection;

What is the error message you get, using your function?
If the message is just "Couldn't delete from zone.", it may be only this that causes a problem.
If you don't get any error, get rid of the @ at the beginning of the mysql_query line.
And in your MySQL query, you should output an error that tells you something, instead of just a message with no real meaning:
[...] or die ('Error with MySQL: '.mysql_error());

hope this helps,
Philippe.

[beardo]

Sorry this is the full function code, I have now ammended and placed your suggested part in for Mysql errors. The global vars were set - I just forgot to put that in my previous post. I ran a test and it outputs:

1
2
3
4
5

Which is my echo "$i"; bit. The SQL bit does not return anything?

function shippingupdatezone($count_cl, $delete, $countryID) {
global $https;
global $connection;
if (!$count_cl) { // Check required values are not present

header("location: ${https}control/shipping-index");
exit;

}
else { // Do the update....>

$count_cl+=1;
for ($i=1; $i<$count_cl; $i++) {
echo "$i<br>";
	if ($delete == "Delete") {
	$sql = "UPDATE country SET zone_id='0' WHERE country_id='$countryID'";
	echo "$sql<br>";
	$result = mysql_query($sql,$connection) or die ('Error with MySQL: '.mysql_error()); 
	}
}

//header("location: ${https}control/shipping-editzone&zone_id=$zone_id");
exit;

}

}

[TheJuice]

Is $delete ever equal to 'Delete'?

Because if it's not, $sql the echo line will never be reached.

After an SQL statement is executed:
If the sql query was a success, $result will be 1 (true), and if it failed it will be 0 (false).

But in your script, when you echo $sql, you only echo some string.
Some I guess that the script never enters this part of the script if you don't get output from there...

[beardo]

Yes delete can equal Delete!

I am basically sending values across like:

delete_1 (2,3 etc.. - might equal Delete otherwise null)

country_id_1 (2,3 etc... all have a numerical value)

The non function code works fine:

if (!$count_cl) { 

header("location: ${https}control/shipping-index");
exit;

}
else { // Do the update....>

$count_cl+=1;
for ($i=1; $i<$count_cl; $i++) {

	if (${"delete_".$i} == "Delete") {
	$sql = "UPDATE country SET zone_id='0' WHERE country_id='${"country_id_".$i}'";
	$result = @mysql_query($sql,$connection) or die("Couldn't delete from zone.");
	}
}

header("location: ${https}control/shipping-editzone&zone_id=$zone_id");
exit;

}

The code above works when not in function form. Note: that there is no other code in the script.

[jackinva]

Hi,

I think your problem is the for loop. You moved it within the function and pass, as the first parameter, the looping end. However, in that function call, you include the $i in the parameter list. That doesn't look right to me. But since you can reference $i without having defined it in PHP, I'm guessing it's passing a variable called $delete and $country_id. Then when $delete ($delete_) is compared to "Delete" it evaluates to false so nothing gets executed.

Hope this is helpful,
Jack

[ahundiak]

I don't think you have the design quite right. Can you show us your loop where you are calling shippingupdatezone() from? And if the answer is that the function is not being called from a loop then the function is not the same as the non-function code.

How did you reach the conclusion that you needed functions to handle variable variables? They are different and basically unrelated concepts.

Just guessing here but I think what you really want to do is to make up an array of arrays with values for zone_id,country_id and delete and get away from using the variable variables completely.

[beardo]

The variable variables work fine when not inside the function! The reason for putting this into a function is to seperate the php code from everything else.

I either have to move the loop out of the function or look at arrays as you suggest.

Thanks for the help with this.