sqlgg_sqlite3.ml

   1 (** sqlgg + ocaml + sqlite3 *)
   2
   3 module S = Sqlite3
   4
   5 type statement = S.stmt
   6 type connection = S.db
   7
   8 type num = int64
   9 type text = string
  10 type any = string
  11
  12 let get_column_Int stmt index =
  13   match S.column stmt index with
  14   | S.Data.INT i -> i
  15   | x -> try Int64.of_string (S.Data.to_string x) with _ -> 0L (* or better fail ? *)
  16
  17 let get_column_Text stmt index =
  18   let x = S.column stmt index in
  19   S.Data.to_string x
  20
  21 let test_ok rc = let ok = rc = S.Rc.OK in assert ok; ok
  22
  23 let bind_param d stmt index =
  24   let rc = S.bind stmt (index+1) d in
  25   test_ok rc
  26
  27 let set_param_null = bind_param S.Data.NULL
  28 let set_param_Text stmt index v = bind_param (S.Data.TEXT v) stmt index
  29 let set_param_Any = set_param_Text
  30 let set_param_Int stmt index v = bind_param (S.Data.INT v) stmt index
  31
  32 let select_exn db sql callback set_params =
  33   let stmt = S.prepare db sql in
  34   set_params stmt;
  35
  36   while S.Rc.ROW = S.step stmt do
  37     callback stmt
  38   done;
  39
  40   test_ok (S.finalize stmt)
  41
  42 let execute_exn db sql set_params =
  43   let stmt = S.prepare db sql in
  44   set_params stmt;
  45
  46   let rc = S.step stmt in
  47   assert (S.Rc.DONE = rc);
  48
  49   test_ok (S.finalize stmt)
  50
  51 (** may @raise exceptions other than Error *)
  52 let select db sql cb p =
  53   try
  54     select_exn db sql cb p
  55   with
  56   | S.Error _ -> false
  57
  58 let execute db sql p =
  59   try
  60     execute_exn db sql p
  61   with
  62   | S.Error _ -> false
  63