table foo01 : {Id : int, Bar : string} PRIMARY KEY Id
table foo10 : {Id : int, Bar : string} PRIMARY KEY Id
table tab : {Id : int, Val : int} PRIMARY KEY Id
fun cache01 () =
res <- oneOrNoRows (SELECT foo01.Bar FROM foo01 WHERE foo01.Id = 43);
return
Reading 1.
{case res of
None => ?
| Some row => {[row.Foo01.Bar]}}
(* fun cache10 () = *)
(* res <- queryX (SELECT foo10.Bar FROM foo10 WHERE foo10.Id = 42) *)
(* (fn row => {[row.Foo10.Bar]}); *)
(* return *)
(* Reading 2. *)
(* {res} *)
(* *)
(* fun cache11 () = *)
(* res <- oneOrNoRows (SELECT foo01.Bar FROM foo01 WHERE foo01.Id = 42); *)
(* bla <- oneOrNoRows (SELECT foo10.Bar FROM foo10 WHERE foo10.Id = 42); *)
(* return *)
(* Reading 1 and 2. *)
(* {case res of *)
(* None => ? *)
(* | Some row => {[row.Foo01.Bar]}} *)
(* {case bla of *)
(* None => ? *)
(* | Some row => {[row.Foo10.Bar]}} *)
(* *)
fun flush01 () =
dml (INSERT INTO foo01 (Id, Bar) VALUES (42, "baz01"));
(* dml (UPDATE foo01 SET Bar = "baz01" WHERE Id = 42); *)
return
Flushed 1!
(* fun flush10 () = *)
(* dml (UPDATE foo10 SET Bar = "baz10" WHERE Id = 42); *)
(* return *)
(* Flushed 2! *)
(* *)
(* fun flush11 () = *)
(* dml (UPDATE foo01 SET Bar = "baz11" WHERE Id = 42); *)
(* dml (UPDATE foo10 SET Bar = "baz11" WHERE Id = 42); *)
(* return *)
(* Flushed 1 and 2! *)
(* *)
fun cache id =
res <- oneOrNoRows (SELECT tab.Val FROM tab WHERE tab.Id = {[id]});
return
Reading {[id]}.
{case res of
None => ?
| Some row => {[row.Tab.Val]}}
fun flush id =
res <- oneOrNoRows (SELECT tab.Val FROM tab WHERE tab.Id = {[id]});
(case res of
None => dml (INSERT INTO tab (Id, Val) VALUES ({[id]}, 0))
| Some row => dml (UPDATE tab SET Val = {[row.Tab.Val + 1]} WHERE Id = {[id]}));
return
(* Flushed {[id]}! *)
{case res of
None => Initialized {[id]}!
| Some row => Incremented {[id]}!}