sqlite - Insert the newset value in a table and drop the old ones -

i have method saves somes records machine in table. however, may insert accident multiple times records same machine in day, want day save newest insert , drop old ones. thought 1 solution:

string sq = "select date, idmachine "           + "from machines_records date = ? , idmachine = ?";   try {                class.forname(typedb);         c = drivermanager.getconnection(path);                     stm = c.preparestatement(sq);           resultset rs = stm.executequery();          if (rs.next()) {                            {                  //call method drop value                } while(rs.next());          }else {                //call method insert value          }                }catch (sqlexception e) {             system.out.println(e.getmessage());         } {             if (stm != null)                 stm.close();             if (c != null)         c.close();   } 

is there better/smartest solution this, can make theses actions in same method?

with unique index (possibly primary key) on date , idmachine use insert ... on duplicate key update, insert when there no entry machine on day or update existing record new data otherwise.

insert machines_records   (machineid, date, data) values   (@id, @date, @data) on duplicate key update data = @data; 

edit: see removed mysql tag. want answer sqlite. in sqlite you'd use insert or replace:

insert or replace machines_records   (machineid, date, data) values   (@id, @date, @data);