datatype list t = Nil | Cons of t * list t
table t : { Id : int, A : string }
PRIMARY KEY Id
fun add id s =
dml (INSERT INTO t (Id, A) VALUES ({[id]}, {[s]}))
fun del id =
dml (DELETE FROM t WHERE t.Id = {[id]})
fun lookup id =
ro <- oneOrNoRows (SELECT t.A FROM t WHERE t.Id = {[id]});
case ro of
None => return None
| Some r => return (Some r.T.A)
fun check ls =
case ls of
Nil => return ()
| Cons (id, ls') =>
ao <- lookup id;
alert (case ao of
None => "Nada"
| Some a => a);
check ls'
fun action () =
idAdd <- source "";
aAdd <- source "";
idDel <- source "";
return