Advance filtering with Dreamweaver cs4, PHP and mysql

Here is the problem:

This is my query which gives me back no data.

SELECT *
FROM photos
WHERE photoTypeID LIKE cat
ORDER BY photoID DESC

variable = cat

Type = integer

default value= -1

run time value = $_POST['cat']

If I change the default value to "%" I get all the data in the Test SQL statement window but then I get a DIVISION BY ZERO on my page.