OHS Harvester 2.3.2 custom search


I’m working on custom themes with OHS (harvesting books from OMP – OAI DC). MysqlIndex works great but the query strings were too complicated (i change the form method to GET).
My goal is to make a simple search form where the url address looks like “base_url/search?title=calculus&publisher=newpress&creator=” then display filtered records. Also i want the query could do sorting & pagination.
Problems: I have no clue to query the records properly. IMO access database directy not a good idea due to parsed contents. I can code but i don’t know where to start, trying to modify mysqlindex but so complex.

Any help would be appreciated.