MathQL 1.3 ready for use

[helm.git] / helm / ocaml / mathql_interpreter / mQIProperty.ml

diff --git a/helm/ocaml/mathql_interpreter/mQIProperty.ml b/helm/ocaml/mathql_interpreter/mQIProperty.ml
index 56a9d64212d44ea9bd0e4de0472b54da0957402f..b07fdd5519343f4a68a270714ccfdfd4ab20e187 100644 (file)
--- a/helm/ocaml/mathql_interpreter/mQIProperty.ml
+++ b/helm/ocaml/mathql_interpreter/mQIProperty.ml
@@ -26,6 +26,7 @@
 
 module M = MathQL
 module P = MQIPostgres
+module C = MQIConn
 module U = MQIUtil
 
 let not_supported s = 
@@ -51,7 +52,11 @@ let cl_print l =
 
 (* PostgreSQL backend  ******************************************************)
 
-let pg_query table cols ct cfl =
+let pg_query h table cols ct cfl =
+   let exec q = 
+      if C.set h C.Log then C.log h (q ^ "\n");
+      P.exec (C.pgc h) q 
+   in
    let rec iter f sep = function
       | []           -> ""
       | [head]       -> f head 
@@ -77,12 +82,21 @@ let pg_query table cols ct cfl =
       | [], llf -> " where " ^ pg_cons_not_l llf
       | lt, llf -> " where " ^ pg_cons lt ^ " and " ^ pg_cons_not_l llf
    in
-   if cols = [] then [] else begin
-      let q = "select " ^ pg_cols ^ " from " ^ table ^ pg_where ^ 
-              " order by " ^ List.hd cols ^ " asc" in
-      prerr_endline q;      
-      P.exec q end
-   
+   if cols = [] then
+      let r = exec ("select count (source) from " ^ table ^ pg_where) in
+      match r with
+         | [[s]] when int_of_string s > 0 -> [[]]
+        | _                              -> []
+   else
+      exec ("select " ^ pg_cols ^ " from " ^ table ^ pg_where ^ 
+            " order by " ^ List.hd cols ^ " asc")
+
+(* Galax backend  ***********************************************************)
+
+let gx_query h table cols ct cfl = not_supported "Galax"
+
+(* Common functions  ********************************************************)
+
 let pg_result distinct subj el res =
   let compose = if distinct then List.map else fun f -> U.mql_iter (fun x -> [f x]) in 
   let get_name = function (p, None) -> p | (_, Some p) -> p in
@@ -131,38 +145,35 @@ let conv = function
    | [_; t]         -> decolon t
    | _              -> not_supported "conv" 
 
-let postgres_single mc ct cfl el t =
+let exec_single h mc ct cfl el t =
    let table = match t with Some t -> decolon t | None -> "objectName" in
    let first = conv mc in
    let mk_con l = List.map (fun (pat, p, v) -> (pat, conv p, v)) l in
    let cons_true = mk_con ct in 
    let cons_false = List.map mk_con cfl in
    let other_cols = List.map (fun (p, _) -> conv p) el in 
-   let cols = if first = "" then other_cols else first :: other_cols in 
-   pg_result false first el (pg_query table cols cons_true cons_false) 
+   let cols = if first = "" then other_cols else first :: other_cols in
+   let low_level = if C.set h C.Galax then gx_query else pg_query in
+   pg_result false first el (low_level h table cols cons_true cons_false) 
    
 let deadline = 100
 
-let postgres refine mc ct cfl el =
-   if refine <> M.RefineExact then not_supported "postgres";   
+let exec h refine mc ct cfl el =
+   if refine <> M.RefineExact then not_supported "exec";   
    let table = get_table mc ct cfl el in
-   let rec postgres_aux ct = match ct with 
+   let rec exec_aux ct = match ct with 
       | (pat, p, v) :: tail when List.length v > deadline ->
-         let single s = postgres_aux ((pat, p, [s]) :: tail) in
+         let single s = exec_aux ((pat, p, [s]) :: tail) in
         U.mql_iter single v
       | _                                                 ->
-         postgres_single mc ct cfl el table
-   in postgres_aux ct   
-
-(* Galax backend  ***********************************************************)
-
-let galax refine mc ct cfl el = not_supported "Galax"
+         exec_single h mc ct cfl el table
+   in exec_aux ct       
 
 (* funzioni vecchie  ********************************************************)
 
-let pg_name s = 
+let pg_name h s = 
    let q = "select id from registry where uri = " ^ P.quote s in
-   match P.exec q with
+   match P.exec h q with
       | [[id]] -> "t" ^ id
       | _      -> ""