From 40098da68420bb08aa0aa0889fa5298fd005c245 Mon Sep 17 00:00:00 2001 From: Adam Chlipala Date: Sat, 3 Dec 2011 17:07:34 -0500 Subject: New 't.*' notation for SELECT --- src/urweb.grm | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 56 insertions(+), 9 deletions(-) (limited to 'src/urweb.grm') diff --git a/src/urweb.grm b/src/urweb.grm index bb9ea18b..22616c79 100644 --- a/src/urweb.grm +++ b/src/urweb.grm @@ -44,6 +44,7 @@ datatype select_item = Field of con * con | Exp of con option * exp | Fields of con * con + | StarFields of con datatype select = Star @@ -65,6 +66,11 @@ fun nameString (c, _) = | CVar (_, x) => x | _ => "?" +datatype tableMode = + Unknown + | Everything + | Selective of con + fun amend_select loc (si, (count, tabs, exps)) = case si of Field (tx, fx) => @@ -73,7 +79,15 @@ fun amend_select loc (si, (count, tabs, exps)) = val (tabs, found) = ListUtil.foldlMap (fn ((tx', c'), found) => if eqTnames (tx, tx') then - ((tx', (CConcat (c, c'), loc)), true) + case c' of + Everything => + (ErrorMsg.errorAt loc + "Mixing specific-field and '*' selection of fields from same table"; + ((tx', c'), found)) + | Unknown => + ((tx', Selective c), true) + | Selective c' => + ((tx', Selective (CConcat (c, c'), loc)), true) else ((tx', c'), found)) false tabs @@ -89,7 +103,15 @@ fun amend_select loc (si, (count, tabs, exps)) = let val (tabs, found) = ListUtil.foldlMap (fn ((tx', c'), found) => if eqTnames (tx, tx') then - ((tx', (CConcat (fs, c'), loc)), true) + case c' of + Everything => + (ErrorMsg.errorAt loc + "Mixing specific-field and '*' selection of fields from same table"; + ((tx', c'), found)) + | Selective c' => + ((tx', Selective (CConcat (fs, c'), loc)), true) + | Unknown => + ((tx', Selective fs), true) else ((tx', c'), found)) false tabs @@ -101,6 +123,17 @@ fun amend_select loc (si, (count, tabs, exps)) = (count, tabs, exps) end + | StarFields tx => + if List.exists (fn (tx', c') => eqTnames (tx, tx') andalso case c' of + Unknown => false + | _ => true) tabs then + (ErrorMsg.errorAt loc "Selection with '*' from table already mentioned in same SELECT clause"; + (count, tabs, exps)) + else if List.all (fn (tx', c') => not (eqTnames (tx, tx'))) tabs then + (ErrorMsg.errorAt loc "Select of all fields from unbound table"; + (count, tabs, exps)) + else + (count, map (fn (tx', c') => (tx', if eqTnames (tx, tx') then Everything else c')) tabs, exps) | Exp (SOME c, e) => (count, tabs, (c, e) :: exps) | Exp (NONE, e) => (count+1, tabs, ((CName (Int.toString count), loc), e) :: exps) @@ -1560,18 +1593,31 @@ query1 : SELECT dopt select FROM tables wopt gopt hopt []) | Items sis => let - val tabs = map (fn nm => (nm, (CRecord [], loc))) (#1 tables) + val tabs = map (fn nm => (nm, Unknown)) (#1 tables) val (_, tabs, exps) = foldl (amend_select loc) (1, tabs, []) sis - val empties = List.mapPartial (fn (nm, (CRecord [], _)) => - SOME nm - | _ => NONE) tabs + val empties = List.mapPartial (fn (nm, c) => + case c of + Unknown => SOME nm + | Selective (CRecord [], _) => SOME nm + | _ => NONE) tabs in (empties, map (fn (nm, c) => (nm, - (CTuple [c, - (CWild (KRecord (KType, loc), loc), - loc)], loc))) tabs, + case c of + Everything => + (CTuple [(CWild (KRecord (KType, loc), loc), loc), + (CRecord [], loc)], loc) + | _ => + let + val c = case c of + Selective c => c + | _ => (CRecord [], loc) + in + (CTuple [c, + (CWild (KRecord (KType, loc), loc), + loc)], loc) + end)) tabs, exps) end @@ -1770,6 +1816,7 @@ seli : tident DOT fident (Field (tident, fident)) | sqlexp (Exp (NONE, sqlexp)) | sqlexp AS fident (Exp (SOME fident, sqlexp)) | tident DOT LBRACE LBRACE cexp RBRACE RBRACE (Fields (tident, cexp)) + | tident DOT STAR (StarFields tident) selis : seli ([seli]) | seli COMMA selis (seli :: selis) -- cgit v1.2.3