This week I was able to complete refactoring sql.php. As the final task I removed the include statements of sql.php in other scripts with function calls to sql.lib.php. And also I started writing unit tests for sql.lib.php. Since I didn't have any experience in writing unit tests I had to spend lot of time on learning. Finally I was able to write few unit test cases and still I am in the process of completing it.
My plans for next week is to refactor tbl_change.php. tbl_change.php is a fairly long script with approximately 400 lines. It contains raw html here and there. I am planning to refacotor the script using extract method.