Adult Shop - PHP/MYSQL Script

Online Adult Shop requires the following php code file to be able to adjust the prices site wide to be able to have a % or $ value of sale. For example the month of June 10% or $10 of each product 1. Php based script that can directly access mysql database. 2. Adjust the data on a table to increase / decrease price value by percentage or dollar value to all products at or per category.