Add between (#127)

* Update between so it works with SQL values

* Add support for composite keys in between clause

* Remove unused values from ERaw in construct

* Update unsafeSqlBinOp to handle composite keys and between to use >=., <=. and &&.

* Support composite keys in unsafeSqlBinOp correctly

* Updated changelog

* Update version number of between to 3.1.0

changelog.md

@@ -6,6 +6,8 @@ Unreleased
 
 - @Vlix
   - [#128](https://github.com/bitemyapp/esqueleto/pull/128): Added `Database.Esqueleto.PostgreSQL.JSON` module with JSON operators and `JSONB` data type.
+- @ibarrae
+  - [#127](https://github.com/bitemyapp/esqueleto/pull/127): Added `between` and support for composite keys in `unsafeSqlBinOp`.
 
 3.0.0
 =======

src/Database/Esqueleto.hs

@@ -44,7 +44,7 @@ module Database.Esqueleto
              , val, isNothing, just, nothing, joinV, withNonNull
              , countRows, count, countDistinct
              , not_, (==.), (>=.), (>.), (<=.), (<.), (!=.), (&&.), (||.)
-             , (+.), (-.), (/.), (*.)
+             , between, (+.), (-.), (/.), (*.)
              , random_, round_, ceiling_, floor_
              , min_, max_, sum_, avg_, castNum, castNumM
              , coalesce, coalesceDefault

src/Database/Esqueleto/Internal/Internal.hs

@@ -455,6 +455,11 @@ not_ (ECompositeKey _) = throw (CompositeKeyErr NotError)
 (*.)  :: PersistField a => SqlExpr (Value a) -> SqlExpr (Value a) -> SqlExpr (Value a)
 (*.)  = unsafeSqlBinOp " * "
 
+-- | @BETWEEN@.
+--
+-- @since: 3.1.0
+between :: PersistField a => SqlExpr (Value a) -> (SqlExpr (Value a), SqlExpr (Value a)) -> SqlExpr (Value Bool)
+a `between` (b, c) = a >=. b &&. a <=. c
 
 random_  :: (PersistField a, Num a) => SqlExpr (Value a)
 random_  = unsafeSqlValue "RANDOM()"
@@ -1242,7 +1247,6 @@ data CompositeKeyError =
   | CombineInsertionError
   | FoldHelpError
   | SqlCaseError
-  | SqlBinOpError
   | SqlCastAsError
   | MakeOnClauseError
   | MakeExcError
@@ -1641,7 +1645,16 @@ unsafeSqlBinOp op (ERaw p1 f1) (ERaw p2 f2) = ERaw Parens f
                  (b2, vals2) = f2 info
              in ( parensM p1 b1 <> op <> parensM p2 b2
                 , vals1 <> vals2 )
-unsafeSqlBinOp _ _ _ = throw (CompositeKeyErr SqlBinOpError)
+unsafeSqlBinOp op a b = unsafeSqlBinOp op (construct a) (construct b)
+    where construct :: SqlExpr (Value a) -> SqlExpr (Value a)
+          construct (ERaw p f)        = ERaw Parens $ \info ->
+            let (b1, vals) = f info
+                build ("?", [PersistList vals']) =
+                  (uncommas $ replicate (length vals') "?", vals')
+                build expr = expr
+             in  build (parensM p b1, vals)
+          construct (ECompositeKey f) =
+            ERaw Parens $ \info -> (uncommas $ f info, mempty)
 {-# INLINE unsafeSqlBinOp #-}
 
 
@@ -2785,4 +2798,3 @@ insertSelect = void . insertSelectCount
 insertSelectCount :: (MonadIO m, PersistEntity a) =>
   SqlQuery (SqlExpr (Insertion a)) -> SqlWriteT m Int64
 insertSelectCount = rawEsqueleto INSERT_INTO . fmap EInsertFinal
-

src/Database/Esqueleto/Internal/Language.hs

@@ -47,7 +47,7 @@ module Database.Esqueleto.Internal.Language
              , val, isNothing, just, nothing, joinV, withNonNull
              , countRows, count, countDistinct
              , not_, (==.), (>=.), (>.), (<=.), (<.), (!=.), (&&.), (||.)
-             , (+.), (-.), (/.), (*.)
+             , between, (+.), (-.), (/.), (*.)
              , random_, round_, ceiling_, floor_
              , min_, max_, sum_, avg_, castNum, castNumM
              , coalesce, coalesceDefault

test/Common/Test.hs

@@ -630,6 +630,54 @@ testSelectWhere run = do
                return p
         liftIO $ ret `shouldBe` [ p3e ]
 
+    describe "when using between" $ do
+      it "works for a simple example with [uses just . val]" $
+        run $ do
+          p1e  <- insert' p1
+          _    <- insert' p2
+          _    <- insert' p3
+          ret  <- select $
+            from $ \p -> do
+              where_ ((p ^. PersonAge) `between` (just $ val 20, just $ val 40))
+              return p
+          liftIO $ ret `shouldBe` [ p1e ]
+      it "works for a proyected fields value" $
+        run $ do
+          _ <- insert' p1 >> insert' p2 >> insert' p3
+          ret <-
+            select $
+            from $ \p -> do
+            where_ $
+              just (p ^. PersonFavNum)
+                `between`
+                  (p ^. PersonAge, p ^.  PersonWeight)
+          liftIO $ ret `shouldBe` []
+      describe "when projecting composite keys" $ do
+        it "works when using composite keys with val" $
+          run $ do
+            insert_ $ Point 1 2 ""
+            ret <-
+              select $
+              from $ \p -> do
+              where_ $
+                p ^. PointId
+                  `between`
+                    ( val $ PointKey 1 2
+                    , val $ PointKey 5 6 )
+            liftIO $ ret `shouldBe` [()]
+        it "works when using ECompositeKey constructor" $
+          run $ do
+            insert_ $ Point 1 2 ""
+            ret <-
+              select $
+              from $ \p -> do
+              where_ $
+                p ^. PointId
+                  `between`
+                    ( EI.ECompositeKey $ const ["3", "4"]
+                    , EI.ECompositeKey $ const ["5", "6"] )
+            liftIO $ ret `shouldBe` []
+
     it "works with avg_" $
       run $ do
         _ <- insert' p1