module Database.Groundhog.Generic.PersistBackendHelpers
(
get
, select
, selectAll
, getBy
, project
, count
, replace
, update
, delete
, insertByAll
, deleteByKey
, countAll
, insertBy
) where
import Database.Groundhog.Core hiding (PersistBackend(..))
import Database.Groundhog.Core (PersistBackend, PhantomDb)
import qualified Database.Groundhog.Core as Core
import Database.Groundhog.Generic
import Database.Groundhog.Generic.Sql
import Control.Monad (liftM, forM, (>=>))
import Data.Maybe (fromJust)
import Data.Monoid
get :: forall m s v . (PersistBackend m, StringLike s, PersistEntity v, PrimitivePersistField (Key v BackendSpecific))
=> (s -> s) -> (forall a . s -> [DbType] -> [PersistValue] -> (RowPopper m -> m a) -> m a) -> Key v BackendSpecific -> m (Maybe v)
get escape queryFunc (k :: Key v BackendSpecific) = do
let e = entityDef (undefined :: v)
let proxy = undefined :: Proxy (PhantomDb m)
let name = persistName (undefined :: v)
if isSimple (constructors e)
then do
let constr = head $ constructors e
let fields = renderFields escape (constrParams constr)
let query = "SELECT " <> fields <> " FROM " <> escape (fromString name) <> " WHERE " <> fromJust (constrId escape constr) <> "=?"
let types = getConstructorTypes constr
x <- queryFunc query types [toPrimitivePersistValue proxy k] id
case x of
Just xs -> liftM (Just . fst) $ fromEntityPersistValues $ PersistInt64 0:xs
Nothing -> return Nothing
else do
let query = "SELECT discr FROM " <> escape (fromString name) <> " WHERE id=?"
x <- queryFunc query [DbInt32] [toPrimitivePersistValue proxy k] id
case x of
Just [discr] -> do
let constructorNum = fromPrimitivePersistValue proxy discr
let constr = constructors e !! constructorNum
let cName = fromString $ name ++ [delim] ++ constrName constr
let fields = renderFields escape (constrParams constr)
let cQuery = "SELECT " <> fields <> " FROM " <> escape cName <> " WHERE " <> fromJust (constrId escape constr) <> "=?"
x2 <- queryFunc cQuery (getConstructorTypes constr) [toPrimitivePersistValue proxy k] id
case x2 of
Just xs -> liftM (Just . fst) $ fromEntityPersistValues $ discr:xs
Nothing -> fail "Missing entry in constructor table"
Just x' -> fail $ "Unexpected number of columns returned: " ++ show x'
Nothing -> return Nothing
select :: forall m s v c opts . (PersistBackend m, StringLike s, PersistEntity v, Constructor c, HasSelectOptions opts v c)
=> (s -> s) -> (forall a . s -> [DbType] -> [PersistValue] -> (RowPopper m -> m a) -> m a) -> s -> (Cond v c -> Maybe (RenderS s)) -> opts -> m [v]
select escape queryFunc noLimit renderCond' options = start where
SelectOptions cond limit offset ords = getSelectOptions options
start = if isSimple (constructors e)
then doSelectQuery (mkQuery name) (0 :: Int)
else let
cName = name ++ [delim] ++ constrName constr
in doSelectQuery (mkQuery cName) $ constrNum constr
e = entityDef (undefined :: v)
proxy = undefined :: Proxy (PhantomDb m)
orders = renderOrders escape ords
name = persistName (undefined :: v)
(lim, limps) = case (limit, offset) of
(Nothing, Nothing) -> ("", [])
(Nothing, o) -> (" " <> noLimit <> " OFFSET ?", [toPrimitivePersistValue proxy o])
(l, Nothing) -> (" LIMIT ?", [toPrimitivePersistValue proxy l])
(l, o) -> (" LIMIT ? OFFSET ?", [toPrimitivePersistValue proxy l, toPrimitivePersistValue proxy o])
cond' = renderCond' cond
fields = renderFields escape (constrParams constr)
mkQuery tname = "SELECT " <> fields <> " FROM " <> escape (fromString tname) <> whereClause <> orders <> lim
whereClause = maybe "" (\c -> " WHERE " <> getQuery c) cond'
doSelectQuery query cNum = queryFunc query types binds $ mapAllRows $ liftM fst . fromEntityPersistValues . (toPrimitivePersistValue proxy cNum:)
binds = maybe id getValues cond' $ limps
constr = constructors e !! phantomConstrNum (undefined :: c a)
types = getConstructorTypes constr
selectAll :: forall m s v . (PersistBackend m, StringLike s, PersistEntity v)
=> (s -> s) -> (forall a . s -> [DbType] -> [PersistValue] -> (RowPopper m -> m a) -> m a) -> m [(AutoKey v, v)]
selectAll escape queryFunc = start where
start = if isSimple (constructors e)
then let
constr = head $ constructors e
fields = maybe id (\key cont -> key <> fromChar ',' <> cont) (constrId escape constr) $ renderFields escape (constrParams constr)
query = "SELECT " <> fields <> " FROM " <> escape (fromString name)
types = maybe id (const $ (DbInt64:)) (constrId escape constr) $ getConstructorTypes constr
in queryFunc query types [] $ mapAllRows $ mkEntity proxy 0
else liftM concat $ forM (zip [0..] (constructors e)) $ \(cNum, constr) -> do
let fields = fromJust (constrId escape constr) <> fromChar ',' <> renderFields escape (constrParams constr)
let cName = fromString $ name ++ [delim] ++ constrName constr
let query = "SELECT " <> fields <> " FROM " <> escape cName
let types = DbInt64:getConstructorTypes constr
queryFunc query types [] $ mapAllRows $ mkEntity proxy cNum
e = entityDef (undefined :: v)
proxy = undefined :: Proxy (PhantomDb m)
name = persistName (undefined :: v)
getBy :: forall m s v u . (PersistBackend m, StringLike s, PersistEntity v, IsUniqueKey (Key v (Unique u)))
=> (s -> s) -> (forall a . s -> [DbType] -> [PersistValue] -> (RowPopper m -> m a) -> m a) -> Key v (Unique u) -> m (Maybe v)
getBy escape queryFunc (k :: Key v (Unique u)) = do
let e = entityDef (undefined :: v)
let name = persistName (undefined :: v)
uniques <- toPersistValues k
let u = (undefined :: Key v (Unique u) -> u (UniqueMarker v)) k
let uFields = foldr (renderChain escape) [] $ projectionFieldChains u []
let cond = intercalateS " AND " $ map (<> "=?") uFields
let constr = head $ constructors e
let fields = renderFields escape (constrParams constr)
let query = "SELECT " <> fields <> " FROM " <> escape (fromString name) <> " WHERE " <> cond
x <- queryFunc query (getConstructorTypes constr) (uniques []) id
case x of
Just xs -> liftM (Just . fst) $ fromEntityPersistValues $ PersistInt64 0:xs
Nothing -> return Nothing
project :: forall m s v c p opts a'. (PersistBackend m, StringLike s, PersistEntity v, Constructor c, Projection p (RestrictionHolder v c) a', HasSelectOptions opts v c)
=> (s -> s) -> (forall a . s -> [DbType] -> [PersistValue] -> (RowPopper m -> m a) -> m a) -> s -> (Cond v c -> Maybe (RenderS s)) -> p -> opts -> m [a']
project escape queryFunc noLimit renderCond' p options = start where
SelectOptions cond limit offset ords = getSelectOptions options
start = doSelectQuery $ if isSimple (constructors e)
then mkQuery name
else let
cName = name ++ [delim] ++ constrName constr
in mkQuery cName
e = entityDef (undefined :: v)
proxy = undefined :: Proxy (PhantomDb m)
orders = renderOrders escape ords
name = persistName (undefined :: v)
(lim, limps) = case (limit, offset) of
(Nothing, Nothing) -> ("", [])
(Nothing, o) -> (" " <> noLimit <> " OFFSET ?", [toPrimitivePersistValue proxy o])
(l, Nothing) -> (" LIMIT ?", [toPrimitivePersistValue proxy l])
(l, o) -> (" LIMIT ? OFFSET ?", [toPrimitivePersistValue proxy l, toPrimitivePersistValue proxy o])
cond' = renderCond' cond
chains = projectionFieldChains p []
fields = intercalateS (fromChar ',') $ foldr (renderChain escape) [] chains
mkQuery tname = "SELECT " <> fields <> " FROM " <> escape (fromString tname) <> whereClause <> orders <> lim
whereClause = maybe "" (\c -> " WHERE " <> getQuery c) cond'
doSelectQuery query = queryFunc query types binds $ mapAllRows $ liftM fst . projectionResult p
binds = maybe id getValues cond' $ limps
constr = constructors e !! phantomConstrNum (undefined :: c a)
types = foldr getDbTypes [] $ map (snd . fst) chains
count :: forall m s v c . (PersistBackend m, StringLike s, PersistEntity v, Constructor c)
=> (s -> s) -> (forall a . s -> [DbType] -> [PersistValue] -> (RowPopper m -> m a) -> m a) -> (Cond v c -> Maybe (RenderS s)) -> Cond v c -> m Int
count escape queryFunc renderCond' (cond :: Cond v c) = do
let e = entityDef (undefined :: v)
let proxy = undefined :: Proxy (PhantomDb m)
let cond' = renderCond' cond
let name = persistName (undefined :: v)
let tname = fromString $ if isSimple (constructors e)
then name
else name ++ [delim] ++ phantomConstrName (undefined :: c a)
let query = "SELECT COUNT(*) FROM " <> escape tname <> whereClause where
whereClause = maybe "" (\c -> " WHERE " <> getQuery c) cond'
x <- queryFunc query [DbInt32] (maybe [] (flip getValues []) cond') id
case x of
Just [num] -> return $ fromPrimitivePersistValue proxy num
Just xs -> fail $ "requested 1 column, returned " ++ show (length xs)
Nothing -> fail $ "COUNT returned no rows"
replace :: forall m s v . (PersistBackend m, StringLike s, PersistEntity v, PrimitivePersistField (Key v BackendSpecific))
=> (s -> s) -> (forall a . s -> [DbType] -> [PersistValue] -> (RowPopper m -> m a) -> m a) -> (s -> [PersistValue] -> m ()) -> (Bool -> String -> ConstructorDef -> s)
-> Key v BackendSpecific -> v -> m ()
replace escape queryFunc execFunc insertIntoConstructorTable k v = do
vals <- toEntityPersistValues' v
let e = entityDef v
let proxy = undefined :: Proxy (PhantomDb m)
let name = persistName v
let constructorNum = fromPrimitivePersistValue proxy (head vals)
let constr = constructors e !! constructorNum
let upds = renderFields (\f -> escape f <> "=?") $ constrParams constr
let mkQuery tname = "UPDATE " <> escape (fromString tname) <> " SET " <> upds <> " WHERE " <> fromString (fromJust $ constrAutoKeyName constr) <> "=?"
if isSimple (constructors e)
then execFunc (mkQuery name) (tail vals ++ [toPrimitivePersistValue proxy k])
else do
let query = "SELECT discr FROM " <> escape (fromString name) <> " WHERE id=?"
x <- queryFunc query [DbInt32] [toPrimitivePersistValue proxy k] (id >=> return . fmap (fromPrimitivePersistValue proxy . head))
case x of
Just discr -> do
let cName = name ++ [delim] ++ constrName constr
if discr == constructorNum
then execFunc (mkQuery cName) (tail vals ++ [toPrimitivePersistValue proxy k])
else do
let insQuery = insertIntoConstructorTable True cName constr
execFunc insQuery (toPrimitivePersistValue proxy k:tail vals)
let oldCName = fromString $ name ++ [delim] ++ constrName (constructors e !! discr)
let delQuery = "DELETE FROM " <> escape oldCName <> " WHERE " <> fromJust (constrId escape constr) <> "=?"
execFunc delQuery [toPrimitivePersistValue proxy k]
let updateDiscrQuery = "UPDATE " <> escape (fromString name) <> " SET discr=? WHERE id=?"
execFunc updateDiscrQuery [head vals, toPrimitivePersistValue proxy k]
Nothing -> return ()
update :: forall m s v c . (PersistBackend m, StringLike s, PersistEntity v, Constructor c)
=> (s -> s) -> (s -> [PersistValue] -> m ()) -> (Cond v c -> Maybe (RenderS s)) -> [Update v c] -> Cond v c -> m ()
update escape execFunc renderCond' upds (cond :: Cond v c) = do
let e = entityDef (undefined :: v)
let proxy = undefined :: Proxy (PhantomDb m)
let name = persistName (undefined :: v)
case renderUpdates proxy escape upds of
Just upds' -> do
let cond' = renderCond' cond
let mkQuery tname = "UPDATE " <> escape tname <> " SET " <> whereClause where
whereClause = maybe (getQuery upds') (\c -> getQuery upds' <> " WHERE " <> getQuery c) cond'
let tname = fromString $ if isSimple (constructors e) then name else name ++ [delim] ++ phantomConstrName (undefined :: c a)
execFunc (mkQuery tname) (getValues upds' <> maybe mempty getValues cond' $ [])
Nothing -> return ()
delete :: forall m s v c . (PersistBackend m, StringLike s, PersistEntity v, Constructor c)
=> (s -> s) -> (s -> [PersistValue] -> m ()) -> (Cond v c -> Maybe (RenderS s)) -> Cond v c -> m ()
delete escape execFunc renderCond' (cond :: Cond v c) = execFunc query (maybe [] (($ []) . getValues) cond') where
e = entityDef (undefined :: v)
constr = head $ constructors e
cond' = renderCond' cond
name = persistName (undefined :: v)
whereClause = maybe "" (\c -> " WHERE " <> getQuery c) cond'
query = if isSimple (constructors e)
then "DELETE FROM " <> escape (fromString name) <> whereClause
else "DELETE FROM " <> escape (fromString name) <> " WHERE id IN(SELECT " <> fromJust (constrId escape constr) <> " FROM " <> escape cName <> whereClause <> ")" where
cName = fromString $ name ++ [delim] ++ phantomConstrName (undefined :: c a)
insertByAll :: forall m s v . (PersistBackend m, StringLike s, PersistEntity v)
=> (s -> s) -> (forall a . s -> [DbType] -> [PersistValue] -> (RowPopper m -> m a) -> m a)
-> v -> m (Either (AutoKey v) (AutoKey v))
insertByAll escape queryFunc v = do
let e = entityDef v
let proxy = undefined :: Proxy (PhantomDb m)
let name = persistName v
let (constructorNum, uniques) = getUniques proxy v
let uniqueDefs = constrUniques $ constructors e !! constructorNum
let cond = intercalateS " OR " $ map (intercalateS " AND " . map (\(fname, _) -> escape (fromString fname) <> "=?")) $ map (\(UniqueDef _ fields) -> fields) uniqueDefs
let ifAbsent tname constr = do
let query = "SELECT " <> maybe "1" id (constrId escape constr) <> " FROM " <> escape (fromString tname) <> " WHERE " <> cond
x <- queryFunc query [DbInt64] (concatMap snd uniques) id
case x of
Nothing -> liftM Right $ Core.insert v
Just [k] -> return $ Left $ fst $ fromPurePersistValues proxy [k]
Just xs -> fail $ "unexpected query result: " ++ show xs
if null uniques
then liftM Right $ Core.insert v
else if isSimple (constructors e)
then do
let constr = head $ constructors e
ifAbsent name constr
else do
let constr = constructors e !! constructorNum
let cName = name ++ [delim] ++ constrName constr
ifAbsent cName constr
deleteByKey :: forall m s v . (PersistBackend m, StringLike s, PersistEntity v, PrimitivePersistField (Key v BackendSpecific))
=> (s -> s) -> (s -> [PersistValue] -> m ()) -> Key v BackendSpecific -> m ()
deleteByKey escape execFunc k = execFunc query [toPrimitivePersistValue proxy k] where
e = entityDef ((undefined :: Key v u -> v) k)
proxy = undefined :: Proxy (PhantomDb m)
constr = head $ constructors e
name = fromString (persistName $ (undefined :: Key v u -> v) k)
query = "DELETE FROM " <> escape name <> " WHERE " <> fromJust (constrId escape constr) <> "=?"
countAll :: forall m s v . (PersistBackend m, StringLike s, PersistEntity v)
=> (s -> s) -> (forall a . s -> [DbType] -> [PersistValue] -> (RowPopper m -> m a) -> m a) -> v -> m Int
countAll escape queryFunc (_ :: v) = do
let proxy = undefined :: Proxy (PhantomDb m)
let name = persistName (undefined :: v)
let query = "SELECT COUNT(*) FROM " <> escape (fromString name)
x <- queryFunc query [DbInt64] [] id
case x of
Just [num] -> return $ fromPrimitivePersistValue proxy num
Just xs -> fail $ "requested 1 column, returned " ++ show (length xs)
Nothing -> fail $ "COUNT returned no rows"
insertBy :: forall m s v u . (PersistBackend m, StringLike s, PersistEntity v, IsUniqueKey (Key v (Unique u)))
=> (s -> s) -> (forall a . s -> [DbType] -> [PersistValue] -> (RowPopper m -> m a) -> m a)
-> u (UniqueMarker v) -> v -> m (Either (AutoKey v) (AutoKey v))
insertBy escape queryFunc u v = do
let e = entityDef v
let proxy = undefined :: Proxy (PhantomDb m)
let name = persistName v
uniques <- toPersistValues $ (extractUnique v `asTypeOf` ((undefined :: u (UniqueMarker v) -> Key v (Unique u)) u))
let fields = foldr (renderChain escape) [] $ projectionFieldChains u []
let cond = intercalateS " AND " $ map (<> "=?") fields
let ifAbsent tname constr = do
let query = "SELECT " <> maybe "1" id (constrId escape constr) <> " FROM " <> escape (fromString tname) <> " WHERE " <> cond
x <- queryFunc query [DbInt64] (uniques []) id
case x of
Nothing -> liftM Right $ Core.insert v
Just [k] -> return $ Left $ fst $ fromPurePersistValues proxy [k]
Just xs -> fail $ "unexpected query result: " ++ show xs
let constr = head $ constructors e
ifAbsent name constr
getConstructorTypes :: ConstructorDef -> [DbType]
getConstructorTypes = foldr getDbTypes [] . map snd . constrParams where
getDbTypes :: DbType -> [DbType] -> [DbType]
getDbTypes typ acc = case typ of
DbEmbedded (EmbeddedDef _ ts) -> foldr (getDbTypes . snd) acc ts
DbEntity (Just (EmbeddedDef _ ts, _)) _ -> foldr (getDbTypes . snd) acc ts
t -> t:acc
constrId :: StringLike s => (s -> s) -> ConstructorDef -> Maybe s
constrId escape = fmap (escape . fromString) . constrAutoKeyName
mkEntity :: (PersistEntity v, PersistBackend m) => Proxy (PhantomDb m) -> Int -> [PersistValue] -> m (AutoKey v, v)
mkEntity proxy i xs = fromEntityPersistValues (toPrimitivePersistValue proxy i:xs') >>= \(v, _) -> return (k, v) where
(k, xs') = fromPurePersistValues proxy xs
toEntityPersistValues' :: (PersistBackend m, PersistEntity v) => v -> m [PersistValue]
toEntityPersistValues' = liftM ($ []) . toEntityPersistValues