From 48cae5396e0ad3f99cd922056eaf0124354f3992 Mon Sep 17 00:00:00 2001
From: Alberto Valverde <alberto@toscat.net>
Date: Wed, 1 Apr 2015 19:06:10 +0200
Subject: [PATCH] allow returning custom id columns from queries if they're not
 composite

---
 src/Database/Esqueleto/Internal/Sql.hs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/Database/Esqueleto/Internal/Sql.hs b/src/Database/Esqueleto/Internal/Sql.hs
index a8971f4..a0d6e74 100644
--- a/src/Database/Esqueleto/Internal/Sql.hs
+++ b/src/Database/Esqueleto/Internal/Sql.hs
@@ -1093,7 +1093,10 @@ instance PersistEntity a => SqlSelect (SqlExpr (Maybe (Entity a))) (Maybe (Entit
 instance PersistField a => SqlSelect (SqlExpr (Value a)) (Value a) where
   sqlSelectCols info (ERaw p f) = let (b, vals) = f info
                                   in (parensM p b, vals)
-  sqlSelectCols _ (ERawList _) = unexpectedCompositeKeyError
+  sqlSelectCols info (ERawList f) = let (b, vals) = f info
+                                    in case b of
+                                         [b'] -> (parensM Parens b', vals)
+                                         _    -> unexpectedCompositeKeyError
   sqlSelectColCount = const 1
   sqlSelectProcessRow [pv] = Value <$> fromPersistValue pv
   sqlSelectProcessRow _    = Left "SqlSelect (Value a): wrong number of columns."