rearrange the test code and add some notes on postgres

tools/Language/SQL/SimpleSQL/FullQueries.lhs

@@ -0,0 +1,38 @@
+
+Some tests for parsing full queries.
+
+> module Language.SQL.SimpleSQL.FullQueries (fullQueriesTests) where
+
+> import Language.SQL.SimpleSQL.TestTypes
+> import Language.SQL.SimpleSQL.Syntax
+
+
+> fullQueriesTests :: TestItem
+> fullQueriesTests = Group "queries" $ map (uncurry TestQueryExpr)
+>     [("select count(*) from t"
+>      ,makeSelect
+>       {qeSelectList = [(Nothing, App "count" [Star])]
+>       ,qeFrom = [TRSimple "t"]
+>       }
+>      )
+
+>     ,("select a, sum(c+d) as s\n\
+>       \  from t,u\n\
+>       \  where a > 5\n\
+>       \  group by a\n\
+>       \  having count(1) > 5\n\
+>       \  order by s"
+>      ,makeSelect
+>       {qeSelectList = [(Nothing, Iden "a")
+>                       ,(Just "s"
+>                        ,App "sum" [BinOp (Iden "c")
+>                                          "+" (Iden "d")])]
+>       ,qeFrom = [TRSimple "t", TRSimple "u"]
+>       ,qeWhere = Just $ BinOp (Iden "a") ">" (NumLit "5")
+>       ,qeGroupBy = [Iden "a"]
+>       ,qeHaving = Just $ BinOp (App "count" [NumLit "1"])
+>                                ">" (NumLit "5")
+>       ,qeOrderBy = [(Iden "s", Asc)]
+>       }
+>      )
+>     ]