adamc@419: functor Make(M : sig
adamc@419:                  type data
adamc@419:                  val inj : sql_injectable data
adamc@419:              end) = struct
adamc@419: 
adamc@419:     type ref = int
adamc@419: 
adamc@419:     sequence s
adamc@419:     table t : { Id : int, Data : M.data }
adamc@419: 
adamc@419:     fun new d =
adamc@419:         id <- nextval s;
adamc@419:         () <- dml (INSERT INTO t (Id, Data) VALUES ({id}, {d}));
adamc@419:         return id
adamc@419: 
adamc@419:     fun read r =
adamc@419:         o <- oneOrNoRows (SELECT t.Data FROM t WHERE t.Id = {r});
adamc@419:         return (case o of
adamc@419:             None => error <xml>You already deleted that ref!</xml>
adamc@419:           | Some r => r.T.Data)
adamc@419: 
adamc@419:     fun write r d =
adamc@419:         dml (UPDATE t SET Data = {d} WHERE Id = {r})
adamc@419: 
adamc@419:     fun delete r =
adamc@419:         dml (DELETE FROM t WHERE Id = {r})
adamc@419: end