add prepare0

src/letsqlite.ml

@@ -55,6 +55,7 @@ let prepare_keep keep db stmt v =
 	try Norm (v,(keep, S.prepare db stmt)) with
 	_ -> Failed Rc.ERROR
 let prepare db s v = prepare_keep false db s v
+let prepare0 db s = prepare db s ()
 let reprepare db stmt (v,(b,s)) =
 	let x = if not b then S.finalize s
 		else Rc.OK

src/letsqlite.mli

@@ -102,6 +102,9 @@ val prepare : Sqlite3.db -> string -> 'a -> 'a stmt_m
     the statement in [s].
 *)
 
+val prepare0 : Sqlite3.db -> string -> unit stmt_m
+(** [prepare0 db stmt] is equivalent to [prepare db stmt ()]. *)
+
 val prepare_keep : bool -> Sqlite3.db -> string -> 'a -> 'a stmt_m
 (** [prepare_keep b] is like [prepare], but [b] is the preserve-on-failure
     file.