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While Loop And Alter Mysql


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I am trying to do a while loop and the loop does fine because I tested it using an echo statement.

However, Every time I remove the echo statement and place a MySQL Alter in there, it does not work.


$d = 1;
while ($d <= $depth)
$w = 1;
while ($w <= $width)
mysql_query("ALTER TABLE `$b` ADD `test$b$w$d` int unsigned not null");


But.... When I use the same Alter Phrase outside the loop it works fine.


What am I missing here? I do not understand why this will not work in the loop but does outside of it!


Thanks for your help!

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The concept of altering a table in a loop is soo scary and soo crazy that I hesitate to even wade into this murky swirling pool ... but what's life without a little adventure, eh?


Question: What are your values for $depth and $width? If they both go into double digits (or higher, you are going to run into duplicate column names here. When $w = 1 and $d = 11, column name = testb111. Then when $w = 11 and $d = 1, column name = testb111 ... oh, look, that's the same name!


If you are seriously creating a table this way,


IT IS WRONG!!!!!!!!!!!!!!!!!!!

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I actually was not going to name it that. I was just using that as an example and you are absolutely correct! Which I never thought about...

Anyways, I need to add these fields to a table and it is dependant on a value from a query.

So, $w could = 2 or 20 and $d the same!

The field would be field$w_$d so they should never duplicate....

Any thoughts how to make this work?

Appreciate the help

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If you tell us why you think you need this "solution", what you're trying to make with it, then I'm sure we can offer you a far better solution to your problem.

I've done quite a bit of work with dynamic database designs, but I've never even dreamed of doing something like this; It's just way too far out there, and almost destined to be a major headache in the future when you're going to maintain it.

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