how can i make the criteria in matlab database variable when i run SQL quiery???

curs = exec(conn, ['SELECT Criteria.Process_ID'... ' , Criteria.Welding_process'... ' , Criteria.Cost'... ' , Criteria.Operator_dependancy'... ' , Criteria.Equipment_Maintenance'... ' , Criteria.Surface_finish'... ' , Criteria.Preparation_Required'... ' , Criteria.Health_and_Safety'... ' , Criteria.Quality'... ' FROM Criteria '... ' WHERE Criteria.Volume_or_area >= 0.1'... ' AND Criteria.PRODVhigh LIKE ''yes'''... ' AND Criteria.APPCMovable_parts LIKE ''yes'''... ' AND Criteria.APPautomotive_industry LIKE ''yes'''... ' AND Criteria.CONFplate_to_plate LIKE ''yes'''... ' AND Criteria.JOINTbut_joint LIKE ''yes'''... ' AND Criteria.POSITIONoverhead LIKE ''yes'''... ' AND Criteria.MATERIALlow_carbon_steel LIKE ''yes'''... ' AND Criteria.THICKNESSminimum <= 5'... ' AND Criteria.THICKNESSmaximum >= 5']); when i try to run the previous sql quiery it runs correctly but when i try to make for example Criteria.MATERIALlow_carbon_steel to be Criteria.h where h is a variable i can change it's value to another string as i want like MATERIALmild_steel where h='MATERIALmild_steel' it gives me no data and it is always 0