add support for odbc outer join syntax

Language/SQL/SimpleSQL/Parse.lhs

@@ -1356,7 +1356,11 @@ aliases.
 >          n <- names
 >          choice [TRFunction n
 >                  <$> parens (commaSep valueExpr)
->                 ,pure $ TRSimple n]] <??> aliasSuffix
+>                 ,pure $ TRSimple n]
+>          -- todo: I think you can only have outer joins inside the oj,
+>          -- not sure.
+>         ,TROdbc <$> (symbol "{" *> keyword_ "oj" *> tref <* symbol "}")
+>         ] <??> aliasSuffix
 >     aliasSuffix = fromAlias <$$> TRAlias
 >     joinTrefSuffix t =
 >         (TRJoin t <$> option False (True <$ keyword_ "natural")

Language/SQL/SimpleSQL/Pretty.lhs

@@ -390,6 +390,7 @@ which have been changed to try to improve the layout of the output.
 >            ,if b then text "natural" else empty
 >            ,joinText jt <+> tr t1
 >            ,joinCond jc]
+>     tr (TROdbc t) = text "{oj" <+> tr t <+> text "}"
 >     joinText jt =
 >       sep [case jt of
 >               JInner -> text "inner"

Language/SQL/SimpleSQL/Syntax.lhs

@@ -430,6 +430,8 @@ I'm not sure if this is valid syntax or not.
 >               | TRFunction [Name] [ValueExpr]
 >                 -- | from lateral t
 >               | TRLateral TableRef
+>                 -- | ODBC {oj t1 left outer join t2 on expr} syntax
+>               | TROdbc TableRef
 >                 deriving (Eq,Show,Read,Data,Typeable)
 
 > -- | Represents an alias for a table valued expression, used in with