main class is MySql method : init() description : constructor for holding mysql db server credidentials

method : create_connection() description : create mysql connection

method : execute_query() description : execute not read-only queries e.g count rows, 'show databaeses', 'select * from table'

method: insert_record() description : insert new record in table (modifies state)

method: update_record() description: update record

method: delete_record() description : deletes record