From 0de82426345870921d8a7725885ac3d092350638 Mon Sep 17 00:00:00 2001
From: Felipe Lessa <felipe.lessa@gmail.com>
Date: Tue, 4 Mar 2014 09:25:14 -0300
Subject: [PATCH] Use persistent 1.3+ new limit/offset func (closes #35).

This code was actually written by @gbwey and it's being
manually merged with some changes by me.
---
 esqueleto.cabal                        |  2 +-
 src/Database/Esqueleto/Internal/Sql.hs | 25 +++++++------------------
 2 files changed, 8 insertions(+), 19 deletions(-)

diff --git a/esqueleto.cabal b/esqueleto.cabal
index 52398cd..86b7dbe 100644
--- a/esqueleto.cabal
+++ b/esqueleto.cabal
@@ -65,7 +65,7 @@ library
   build-depends:
       base                 >= 4.5    && < 4.8
     , text                 >= 0.11
-    , persistent           >= 1.2    && < 1.4
+    , persistent           >= 1.3    && < 1.4
     , transformers         >= 0.2
     , unordered-containers >= 0.2
     , tagged               >= 0.2
diff --git a/src/Database/Esqueleto/Internal/Sql.hs b/src/Database/Esqueleto/Internal/Sql.hs
index a7865f7..cdde68d 100644
--- a/src/Database/Esqueleto/Internal/Sql.hs
+++ b/src/Database/Esqueleto/Internal/Sql.hs
@@ -65,7 +65,6 @@ import qualified Data.HashSet as HS
 import qualified Data.Text as T
 import qualified Data.Text.Lazy as TL
 import qualified Data.Text.Lazy.Builder as TLB
-import qualified Data.Text.Lazy.Builder.Int as TLBI
 
 import Database.Esqueleto.Internal.Language
 
@@ -782,7 +781,7 @@ toRawSql mode (conn, firstIdentState) query =
       , makeGroupBy    info groupByClause
       , makeHaving     info havingClause
       , makeOrderBy    info orderByClauses
-      , makeLimit      info limitClause
+      , makeLimit      info limitClause orderByClauses
       ]
 
 
@@ -894,22 +893,12 @@ makeOrderBy info os = first ("\nORDER BY " <>) $ uncommas' (map mk os)
     orderByType DESC = " DESC"
 
 
-makeLimit :: IdentInfo -> LimitClause -> (TLB.Builder, [PersistValue])
-makeLimit _    (Limit Nothing Nothing)  = mempty
-makeLimit _    (Limit Nothing (Just 0)) = mempty
-makeLimit info (Limit ml      mo)       = (ret, mempty)
-  where
-    ret = TLB.singleton '\n' <> (limitTLB <> offsetTLB)
-
-    limitTLB =
-      case ml of
-        Just l  -> "LIMIT " <> TLBI.decimal l
-        Nothing -> TLB.fromText (connNoLimit $ fst info)
-
-    offsetTLB =
-      case mo of
-        Just o  -> " OFFSET " <> TLBI.decimal o
-        Nothing -> mempty
+makeLimit :: IdentInfo -> LimitClause -> [OrderByClause] -> (TLB.Builder, [PersistValue])
+makeLimit (conn,_) (Limit ml mo) orderByClauses =
+  let limitRaw = connLimitOffset conn (v ml, v mo) hasOrderClause "\n"
+      hasOrderClause = not (null orderByClauses)
+      v = maybe 0 fromIntegral
+  in (TLB.fromText limitRaw, mempty)
 
 
 parens :: TLB.Builder -> TLB.Builder