'dummy' search string

[Anon]

Hi,
I am trying to make a standard query to update forms in PhP - MySQL. Therefor I want to check wether a user has selected a certain option, or needs all data to be displayed. If he wants all data, I want to put in a searchvalue which basically means 'all'. I am not sure how to explain, so here is the code I am trying to get to work:

<?

// More code here...

If ($AllSub==1) { //If all subjects
$Sub = "%";
}

// What should I put between the quotes for the database to return all values for $Sub??

$Input_query = " where Subject.Subjects = '$Sub' ";

// More code here
?>

Hop e I made things more or less clear.

[Anon]

When comparing strings i think you need to use like and not =, but i\'m not 100% sure.

[Anon]

I tried this. Unfortunately, that is not the problem.
The comparing works fine (If I actually have a string in the variable). If there is no searchstring, and the "%" is entered as a search string, I get an error message for the line
$Sub = "%";
So appearently I cannot use the % signal as a 'dummy' / 'use all' sign when building a query..

Any other ideas??

J.

[Anon]

What's the error that you get?

Diego