Script repeats itself - why?

[Magic2K2]

I've had this problem for a while. Sometimes I run an update script and it repeats itself for some reason and inserts everything into the DB twice or more. It makes no sense at all. At the end of the condition, it is supposed to redirect to another page, but it's like it ignores that and randomly goes back and repeats the SQL queries.

[warjockey]

can we see the code?

[Magic2K2]

Oh, to clarify...I don't see how it can be a coding issue because sometimes it works properly and sometimes it does not. There are a lot of SQL queries for it to execute so could this be some type of timeout?

[jaswinder_rana]

it might not be a syntax error BUt it can be alogic error. unless you post your code, none can see what's going on and no one can try to fix it.

[shakin]

Maybe the user is clicking the submit button twice. That happens all the time. An easy workaround is to disable the submit button using javascript when it's clicked using the onclick event. If you disable it on a timer for, say, 10 seconds, it would give the user the opportunity to re-submit the data if there is an error, but stop them from clicking twice too quickly.

[Magic2K2]

It's not the submit button being pressed twice because it's an administrative tool that only I use! Here is the code with certain things edited out for security:

else if ($step == 3)
{
    $sql = str_replace("\\", "", $sql);
    $commands = explode(";", $sql);
    for ($x = 0; $commands[$x]; $x++)
        mysql_query($commands[$x]);

//// LARGE PORTION EDITED OUT

    redirect();

} 

I edited out a large portion, but the mysql_query you see above is where the problem occurs. $sql is valid sql passed from the previous page. What happens is I will run the script and I'll notice that it executed all the SQL commands twice or more. So, I delete those rows in the DB manually and then run the exact same script again and BINGO it works. Today I decided to post about it because it did the double insert thing like 10 straight times and was getting on my nerves, but on the 11th time it worked properly.

[chatmasta]

First of all, you can still press the submit button twice. You aren't God.

Second of all, just post the whole script... It will show up with a scrollbar anyway, it won't take up tons of space or anything.

[DMacedo]

for ($x = 0; $commands[$x]; $x++) 

You have to make the middle expression evaluate as FALSE at some point in order to break the loop. That means it HAS to be an expression, and one that evaluates false or you'll be stuck!

I believe you must be looking for replacing:

$commands[$x] 

with:

$x < sizeof($commands) 

This will evaluate as false when $x is the size of the $commands array, meaning the last command was executed!
For more information: http://php.net/for

[Magic2K2]

Thanks DMacedo, I'll do that. I'm still curious why the script works sometimes and sometimes does not, though.