From b68c116839cf852832cef28f3cd479ac7622293c Mon Sep 17 00:00:00 2001
From: Jake Wheat <jakewheatmail@gmail.com>
Date: Thu, 19 Dec 2013 10:44:20 +0200
Subject: [PATCH] add support for ? for parameterized queries
---
Language/SQL/SimpleSQL/Fixity.lhs | 1 +
Language/SQL/SimpleSQL/Parser.lhs | 8 ++++++++
Language/SQL/SimpleSQL/Pretty.lhs | 1 +
Language/SQL/SimpleSQL/Syntax.lhs | 1 +
tools/Language/SQL/SimpleSQL/ScalarExprs.lhs | 7 +++++++
5 files changed, 18 insertions(+)
diff --git a/Language/SQL/SimpleSQL/Fixity.lhs b/Language/SQL/SimpleSQL/Fixity.lhs
index 58a38d5..77b01e5 100644
--- a/Language/SQL/SimpleSQL/Fixity.lhs
+++ b/Language/SQL/SimpleSQL/Fixity.lhs
@@ -78,6 +78,7 @@ the fixity code.
> -- TODO fix me
> (SpecialOpK {}) -> str ('v':show e)
> Iden {} -> str ('v':show e)
+> Parameter -> str ('v':show e)
> StringLit {} -> str ('v':show e)
> NumLit {} -> str ('v':show e)
> App n es -> HSE.App (var ('f':name n)) $ ltoh es
diff --git a/Language/SQL/SimpleSQL/Parser.lhs b/Language/SQL/SimpleSQL/Parser.lhs
index c88c158..1104c1c 100644
--- a/Language/SQL/SimpleSQL/Parser.lhs
+++ b/Language/SQL/SimpleSQL/Parser.lhs
@@ -137,6 +137,13 @@ in any scalar expression context.
> star :: P ScalarExpr
> star = Star <$ symbol "*"
+== parameter
+
+use in e.g. select * from t where a = ?
+
+> parameter :: P ScalarExpr
+> parameter = Parameter <$ symbol "?"
+
== function application, aggregates and windows
this represents anything which syntactically looks like regular C
@@ -591,6 +598,7 @@ could at least do with some heavy explanation.
> factor :: P ScalarExpr
> factor = choice [literal
+> ,parameter
> ,scase
> ,cast
> ,try specialOpKs
diff --git a/Language/SQL/SimpleSQL/Pretty.lhs b/Language/SQL/SimpleSQL/Pretty.lhs
index c0e86b2..0eff223 100644
--- a/Language/SQL/SimpleSQL/Pretty.lhs
+++ b/Language/SQL/SimpleSQL/Pretty.lhs
@@ -40,6 +40,7 @@
> <+> maybe empty (parens . text . show ) p
> scalarExpr (Iden i) = name i
> scalarExpr Star = text "*"
+> scalarExpr Parameter = text "?"
> scalarExpr (App f es) = name f <> parens (commaSep (map scalarExpr es))
diff --git a/Language/SQL/SimpleSQL/Syntax.lhs b/Language/SQL/SimpleSQL/Syntax.lhs
index d461896..2f749db 100644
--- a/Language/SQL/SimpleSQL/Syntax.lhs
+++ b/Language/SQL/SimpleSQL/Syntax.lhs
@@ -115,6 +115,7 @@
> -- | in list literal and in subquery, if the bool is false it
> -- means not in was used ('a not in (1,2)')
> | In Bool ScalarExpr InPredValue
+> | Parameter -- ^ Represents a ? in a parameterized query
> deriving (Eq,Show,Read)
> -- | Represents an identifier name, which can be quoted or unquoted.
diff --git a/tools/Language/SQL/SimpleSQL/ScalarExprs.lhs b/tools/Language/SQL/SimpleSQL/ScalarExprs.lhs
index 0e13325..6c13b01 100644
--- a/tools/Language/SQL/SimpleSQL/ScalarExprs.lhs
+++ b/tools/Language/SQL/SimpleSQL/ScalarExprs.lhs
@@ -12,6 +12,7 @@ Tests for parsing scalar expressions
> [literals
> ,identifiers
> ,star
+> ,parameter
> ,dots
> ,app
> ,caseexp
@@ -56,6 +57,12 @@ Tests for parsing scalar expressions
> --,("ROW(t.*,42)", App "ROW" [Star2 "t", NumLit "42"])
> ]
+> parameter :: TestItem
+> parameter = Group "parameter" $ map (uncurry TestScalarExpr)
+> [("?", Parameter)
+> ]
+
+
> dots :: TestItem
> dots = Group "dot" $ map (uncurry TestScalarExpr)
> [("t.a", BinOp (Iden "t") "." (Iden "a"))