What is a good (free) tool to perform crud operations using PHP on a mySQL table?

Ideally the use of AJAX would be ideal to make this as simple as possible. I want an easy "admin" interface so a subset of users can have direct access to their data. They need to be able to "C"reate new rows (add data), "R"ead all rows (view the table), "U"pdate rows (edit), and "D"elete rows. Any good suggestions? I know there must be open source solutions out there! Again -- if it uses AJAX that would be a plus. I want a very simple interface to access the data using PHP. A couple lines of code would be ideal....