Ur/Web: demo/more/orm.ur annotate

Basic CRUD operations in Orm

author	Adam Chlipala <adamc@hcoop.net>
date	Mon, 05 Oct 2009 17:00:04 -0400
parents	6dd122f10c0c
children	0bdc4d538f1c

rev	line source
adamc@987	1 con link = fn t :: Type => unit
adamc@987	2
adamc@987	3 con meta = fn col :: Type => {
adamc@987	4 Link : link col,
adamc@987	5 Inj : sql_injectable col
adamc@987	6 }
adamc@987	7
adamc@987	8 functor Table(M : sig
adamc@987	9 con cols :: {Type}
adamc@987	10 val cols : $(map meta cols)
adamc@987	11 constraint [Id] ~ cols
adamc@987	12 val folder : folder cols
adamc@987	13 end) = struct
adamc@987	14 type id = int
adamc@987	15 val inj = _
adamc@987	16 val id : meta id = {Link = (),
adamc@987	17 Inj = inj}
adamc@987	18
adamc@987	19 sequence s
adamc@987	20 table t : ([Id = id] ++ M.cols)
adamc@987	21
adamc@988	22 type row = $([Id = id] ++ M.cols)
adamc@988	23
adamc@988	24 fun ensql [avail] (r : $M.cols) : $(map (sql_exp avail [] []) M.cols) =
adamc@988	25 map2 [meta] [Top.id] [sql_exp avail [] []]
adamc@988	26 (fn [t] meta v => @sql_inject meta.Inj v)
adamc@988	27 [_] M.folder M.cols r
adamc@988	28
adamc@987	29 fun create (r : $M.cols) =
adamc@987	30 id <- nextval s;
adamc@988	31 dml (insert t ({Id = sql_inject id} ++ ensql r));
adamc@988	32 return ({Id = id} ++ r)
adamc@988	33
adamc@988	34 fun delete r = dml (DELETE FROM t WHERE t.Id = {[r.Id]})
adamc@988	35
adamc@988	36 fun save r = dml (update [M.cols] ! (ensql (r -- #Id)) t (WHERE T.Id = {[r.Id]}))
adamc@988	37
adamc@988	38 fun lookup id =
adamc@988	39 ro <- oneOrNoRows (SELECT * FROM t WHERE t.Id = {[id]});
adamc@988	40 return (Option.mp (fn r => r.T) ro)
adamc@988	41
adamc@988	42 val list = query (SELECT * FROM t) (fn r ls => return (r.T :: ls)) []
adamc@987	43 end

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