esqueleto/src/Database/Esqueleto/Internal/Sql.hs
2017-06-21 11:28:46 -06:00

1765 lines
60 KiB
Haskell

{-# LANGUAGE ConstraintKinds
, EmptyDataDecls
, FlexibleContexts
, FlexibleInstances
, FunctionalDependencies
, GADTs
, MultiParamTypeClasses
, OverloadedStrings
, UndecidableInstances
, ScopedTypeVariables
, InstanceSigs
, Rank2Types
#-}
-- | This is an internal module, anything exported by this module
-- may change without a major version bump. Please use only
-- "Database.Esqueleto" if possible.
module Database.Esqueleto.Internal.Sql
( -- * The pretty face
SqlQuery
, SqlExpr
, SqlEntity
, select
, selectSource
, selectDistinct
, selectDistinctSource
, delete
, deleteCount
, update
, updateCount
, insertSelectDistinct
, insertSelect
, insertSelectCount
-- * The guts
, unsafeSqlCase
, unsafeSqlBinOp
, unsafeSqlBinOpComposite
, unsafeSqlValue
, unsafeSqlFunction
, unsafeSqlExtractSubField
, UnsafeSqlFunctionArgument
, rawSelectSource
, runSource
, rawEsqueleto
, toRawSql
, Mode(..)
, IdentState
, initialIdentState
, IdentInfo
, SqlSelect(..)
, veryUnsafeCoerceSqlExprValue
, veryUnsafeCoerceSqlExprValueList
) where
import Control.Arrow ((***), first)
import Control.Exception (throw, throwIO)
import Control.Monad (ap, MonadPlus(..), void, join)
import Control.Monad.IO.Class (MonadIO(..))
import Control.Monad.Trans.Class (lift)
import Control.Monad.Trans.Resource (MonadResource, release)
import Data.Acquire (with, allocateAcquire, Acquire)
import Data.Int (Int64)
import Data.List (intersperse)
import Data.Monoid (Last(..), (<>))
import Data.Proxy (Proxy(..))
import Database.Esqueleto.Internal.PersistentImport
import Database.Persist.Sql.Util (entityColumnNames, entityColumnCount, parseEntityValues, isIdField, hasCompositeKey)
import qualified Control.Monad.Trans.Reader as R
import qualified Control.Monad.Trans.State as S
import qualified Control.Monad.Trans.Writer as W
import qualified Data.Conduit as C
import qualified Data.Conduit.List as CL
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 Database.Esqueleto.Internal.Language
-- | SQL backend for @esqueleto@ using 'SqlPersistT'.
newtype SqlQuery a =
Q { unQ :: W.WriterT SideData (S.State IdentState) a }
instance Functor SqlQuery where
fmap f = Q . fmap f . unQ
instance Monad SqlQuery where
return = Q . return
m >>= f = Q (unQ m >>= unQ . f)
instance Applicative SqlQuery where
pure = return
(<*>) = ap
-- | Constraint synonym for @persistent@ entities whose backend
-- is 'SqlPersistT'.
type SqlEntity ent = (PersistEntity ent, PersistEntityBackend ent ~ SqlBackend)
----------------------------------------------------------------------
-- | Side data written by 'SqlQuery'.
data SideData = SideData { sdDistinctClause :: !DistinctClause
, sdFromClause :: ![FromClause]
, sdSetClause :: ![SetClause]
, sdWhereClause :: !WhereClause
, sdGroupByClause :: !GroupByClause
, sdHavingClause :: !HavingClause
, sdOrderByClause :: ![OrderByClause]
, sdLimitClause :: !LimitClause
, sdLockingClause :: !LockingClause
}
instance Monoid SideData where
mempty = SideData mempty mempty mempty mempty mempty mempty mempty mempty mempty
SideData d f s w g h o l k `mappend` SideData d' f' s' w' g' h' o' l' k' =
SideData (d <> d') (f <> f') (s <> s') (w <> w') (g <> g') (h <> h') (o <> o') (l <> l') (k <> k')
-- | The @DISTINCT@ "clause".
data DistinctClause =
DistinctAll -- ^ The default, everything.
| DistinctStandard -- ^ Only @DISTINCT@, SQL standard.
| DistinctOn [SqlExpr DistinctOn] -- ^ @DISTINCT ON@, PostgreSQL extension.
instance Monoid DistinctClause where
mempty = DistinctAll
DistinctOn a `mappend` DistinctOn b = DistinctOn (a <> b)
DistinctOn a `mappend` _ = DistinctOn a
DistinctStandard `mappend` _ = DistinctStandard
DistinctAll `mappend` b = b
-- | A part of a @FROM@ clause.
data FromClause =
FromStart Ident EntityDef
| FromJoin FromClause JoinKind FromClause (Maybe (SqlExpr (Value Bool)))
| OnClause (SqlExpr (Value Bool))
-- | A part of a @SET@ clause.
newtype SetClause = SetClause (SqlExpr (Value ()))
-- | Collect 'OnClause's on 'FromJoin's. Returns the first
-- unmatched 'OnClause's data on error. Returns a list without
-- 'OnClauses' on success.
collectOnClauses :: [FromClause] -> Either (SqlExpr (Value Bool)) [FromClause]
collectOnClauses = go []
where
go [] (f@(FromStart _ _):fs) = fmap (f:) (go [] fs) -- fast path
go acc (OnClause expr :fs) = findMatching acc expr >>= flip go fs
go acc (f:fs) = go (f:acc) fs
go acc [] = return $ reverse acc
findMatching (f : acc) expr =
case tryMatch expr f of
Just f' -> return (f' : acc)
Nothing -> (f:) <$> findMatching acc expr
findMatching [] expr = Left expr
tryMatch expr (FromJoin l k r onClause) =
matchR `mplus` matchC `mplus` matchL -- right to left
where
matchR = (\r' -> FromJoin l k r' onClause) <$> tryMatch expr r
matchL = (\l' -> FromJoin l' k r onClause) <$> tryMatch expr l
matchC = case onClause of
Nothing | k /= CrossJoinKind
-> return (FromJoin l k r (Just expr))
| otherwise -> mzero
Just _ -> mzero
tryMatch _ _ = mzero
-- | A complete @WHERE@ clause.
data WhereClause = Where (SqlExpr (Value Bool))
| NoWhere
instance Monoid WhereClause where
mempty = NoWhere
NoWhere `mappend` w = w
w `mappend` NoWhere = w
Where e1 `mappend` Where e2 = Where (e1 &&. e2)
-- | A @GROUP BY@ clause.
newtype GroupByClause = GroupBy [SomeValue SqlExpr]
instance Monoid GroupByClause where
mempty = GroupBy []
GroupBy fs `mappend` GroupBy fs' = GroupBy (fs <> fs')
-- | A @HAVING@ cause.
type HavingClause = WhereClause
-- | A @ORDER BY@ clause.
type OrderByClause = SqlExpr OrderBy
-- | A @LIMIT@ clause.
data LimitClause = Limit (Maybe Int64) (Maybe Int64)
instance Monoid LimitClause where
mempty = Limit mzero mzero
Limit l1 o1 `mappend` Limit l2 o2 =
Limit (l2 `mplus` l1) (o2 `mplus` o1)
-- More than one 'limit' or 'offset' is issued, we want to
-- keep the latest one. That's why we use mplus with
-- "reversed" arguments.
-- | A locking clause.
type LockingClause = Last LockingKind
----------------------------------------------------------------------
-- | Identifier used for table names.
newtype Ident = I T.Text
-- | List of identifiers already in use and supply of temporary
-- identifiers.
newtype IdentState = IdentState { inUse :: HS.HashSet T.Text }
initialIdentState :: IdentState
initialIdentState = IdentState mempty
-- | Create a fresh 'Ident'. If possible, use the given
-- 'DBName'.
newIdentFor :: DBName -> SqlQuery Ident
newIdentFor = Q . lift . try . unDBName
where
try orig = do
s <- S.get
let go (t:ts) | t `HS.member` inUse s = go ts
| otherwise = use t
go [] = error "Esqueleto/Sql/newIdentFor: never here"
go (possibilities orig)
possibilities t = t : map addNum [2..]
where
addNum :: Int -> T.Text
addNum = T.append t . T.pack . show
use t = do
S.modify (\s -> s { inUse = HS.insert t (inUse s) })
return (I t)
-- | Information needed to escape and use identifiers.
type IdentInfo = (SqlBackend, IdentState)
-- | Use an identifier.
useIdent :: IdentInfo -> Ident -> TLB.Builder
useIdent info (I ident) = fromDBName info $ DBName ident
----------------------------------------------------------------------
-- | An expression on the SQL backend.
--
-- There are many comments describing the constructors of this
-- data type. However, Haddock doesn't like GADTs, so you'll have to read them by hitting \"Source\".
data SqlExpr a where
-- An entity, created by 'from' (cf. 'fromStart').
EEntity :: Ident -> SqlExpr (Entity val)
-- Just a tag stating that something is nullable.
EMaybe :: SqlExpr a -> SqlExpr (Maybe a)
-- Raw expression: states whether parenthesis are needed
-- around this expression, and takes information about the SQL
-- connection (mainly for escaping names) and returns both an
-- string ('TLB.Builder') and a list of values to be
-- interpolated by the SQL backend.
ERaw :: NeedParens -> (IdentInfo -> (TLB.Builder, [PersistValue])) -> SqlExpr (Value a)
-- A composite key.
--
-- Persistent uses the same 'PersistList' constructor for both
-- fields which are (homogeneous) lists of values and the
-- (probably heterogeneous) values of a composite primary key.
--
-- We need to treat composite keys as fields. For example, we
-- have to support using ==., otherwise you wouldn't be able to
-- join. OTOH, lists of values should be treated exactly the
-- same as any other scalar value.
--
-- In particular, this is valid for persistent via rawSql for
-- an F field that is a list:
--
-- A.F in ? -- [PersistList [foo, bar]]
--
-- However, this is not for a composite key entity:
--
-- A.ID = ? -- [PersistList [foo, bar]]
--
-- The ID field doesn't exist on the DB for a composite key
-- table, it exists only on the Haskell side. Those variations
-- also don't work:
--
-- (A.KeyA, A.KeyB) = ? -- [PersistList [foo, bar]]
-- [A.KeyA, A.KeyB] = ? -- [PersistList [foo, bar]]
--
-- We have to generate:
--
-- A.KeyA = ? AND A.KeyB = ? -- [foo, bar]
--
-- Note that the PersistList had to be deconstructed into its
-- components.
--
-- In order to disambiguate behaviors, this constructor is used
-- /only/ to represent a composite field access. It does not
-- represent a 'PersistList', not even if the 'PersistList' is
-- used in the context of a composite key. That's because it's
-- impossible, e.g., for 'val' to disambiguate between these
-- uses.
ECompositeKey :: (IdentInfo -> [TLB.Builder]) -> SqlExpr (Value a)
-- 'EList' and 'EEmptyList' are used by list operators.
EList :: SqlExpr (Value a) -> SqlExpr (ValueList a)
EEmptyList :: SqlExpr (ValueList a)
-- A 'SqlExpr' accepted only by 'orderBy'.
EOrderBy :: OrderByType -> SqlExpr (Value a) -> SqlExpr OrderBy
EOrderRandom :: SqlExpr OrderBy
-- A 'SqlExpr' accepted only by 'distinctOn'.
EDistinctOn :: SqlExpr (Value a) -> SqlExpr DistinctOn
-- A 'SqlExpr' accepted only by 'set'.
ESet :: (SqlExpr (Entity val) -> SqlExpr (Value ())) -> SqlExpr (Update val)
-- An internal 'SqlExpr' used by the 'from' hack.
EPreprocessedFrom :: a -> FromClause -> SqlExpr (PreprocessedFrom a)
-- Used by 'insertSelect'.
EInsert :: Proxy a -> (IdentInfo -> (TLB.Builder, [PersistValue])) -> SqlExpr (Insertion a)
EInsertFinal :: PersistEntity a => SqlExpr (Insertion a) -> SqlExpr InsertFinal
-- | Phantom type used to mark a @INSERT INTO@ query.
data InsertFinal
data NeedParens = Parens | Never
parensM :: NeedParens -> TLB.Builder -> TLB.Builder
parensM Never = id
parensM Parens = parens
data OrderByType = ASC | DESC
instance Esqueleto SqlQuery SqlExpr SqlBackend where
fromStart = x
where
x = do
let ed = entityDef (getVal x)
ident <- newIdentFor (entityDB ed)
let ret = EEntity ident
from_ = FromStart ident ed
return (EPreprocessedFrom ret from_)
getVal :: SqlQuery (SqlExpr (PreprocessedFrom (SqlExpr (Entity a)))) -> Proxy a
getVal = const Proxy
fromStartMaybe = maybelize <$> fromStart
where
maybelize :: SqlExpr (PreprocessedFrom (SqlExpr (Entity a)))
-> SqlExpr (PreprocessedFrom (SqlExpr (Maybe (Entity a))))
maybelize (EPreprocessedFrom ret from_) = EPreprocessedFrom (EMaybe ret) from_
fromJoin (EPreprocessedFrom lhsRet lhsFrom)
(EPreprocessedFrom rhsRet rhsFrom) = Q $ do
let ret = smartJoin lhsRet rhsRet
from_ = FromJoin lhsFrom -- LHS
(reifyJoinKind ret) -- JOIN
rhsFrom -- RHS
Nothing -- ON
return (EPreprocessedFrom ret from_)
fromFinish (EPreprocessedFrom ret from_) = Q $ do
W.tell mempty { sdFromClause = [from_] }
return ret
where_ expr = Q $ W.tell mempty { sdWhereClause = Where expr }
on expr = Q $ W.tell mempty { sdFromClause = [OnClause expr] }
groupBy expr = Q $ W.tell mempty { sdGroupByClause = GroupBy $ toSomeValues expr }
having expr = Q $ W.tell mempty { sdHavingClause = Where expr }
locking kind = Q $ W.tell mempty { sdLockingClause = Last (Just kind) }
orderBy exprs = Q $ W.tell mempty { sdOrderByClause = exprs }
asc = EOrderBy ASC
desc = EOrderBy DESC
rand = EOrderRandom
limit n = Q $ W.tell mempty { sdLimitClause = Limit (Just n) Nothing }
offset n = Q $ W.tell mempty { sdLimitClause = Limit Nothing (Just n) }
distinct act = Q (W.tell mempty { sdDistinctClause = DistinctStandard }) >> act
distinctOn exprs act = Q (W.tell mempty { sdDistinctClause = DistinctOn exprs }) >> act
don = EDistinctOn
distinctOnOrderBy exprs act =
distinctOn (toDistinctOn <$> exprs) $ do
orderBy exprs
act
where
toDistinctOn :: SqlExpr OrderBy -> SqlExpr DistinctOn
toDistinctOn (EOrderBy _ f) = EDistinctOn f
sub_select = sub SELECT
sub_selectDistinct = sub_select . distinct
(^.) :: forall val typ. (PersistEntity val, PersistField typ)
=> SqlExpr (Entity val) -> EntityField val typ -> SqlExpr (Value typ)
EEntity ident ^. field
| isComposite = ECompositeKey $ \info -> dot info <$> compositeFields pdef
| otherwise = ERaw Never $ \info -> (dot info $ persistFieldDef field, [])
where
isComposite = isIdField field && hasCompositeKey ed
dot info x = useIdent info ident <> "." <> fromDBName info (fieldDB x)
ed = entityDef $ getEntityVal (Proxy :: Proxy (SqlExpr (Entity val)))
Just pdef = entityPrimary ed
EMaybe r ?. field = just (r ^. field)
val v = ERaw Never $ const ("?", [toPersistValue v])
isNothing (ERaw p f) = ERaw Parens $ first ((<> " IS NULL") . parensM p) . f
isNothing (ECompositeKey f) = ERaw Parens $ flip (,) [] . (intersperseB " AND " . map (<> " IS NULL")) . f
just (ERaw p f) = ERaw p f
just (ECompositeKey f) = ECompositeKey f
nothing = unsafeSqlValue "NULL"
joinV (ERaw p f) = ERaw p f
joinV (ECompositeKey f) = ECompositeKey f
countRows = unsafeSqlValue "COUNT(*)"
count = countHelper "" ""
countDistinct = countHelper "(DISTINCT " ")"
not_ (ERaw p f) = ERaw Never $ \info -> let (b, vals) = f info
in ("NOT " <> parensM p b, vals)
not_ (ECompositeKey _) = unexpectedCompositeKeyError "not_"
(==.) = unsafeSqlBinOpComposite " = " " AND "
(!=.) = unsafeSqlBinOpComposite " != " " OR "
(>=.) = unsafeSqlBinOp " >= "
(>.) = unsafeSqlBinOp " > "
(<=.) = unsafeSqlBinOp " <= "
(<.) = unsafeSqlBinOp " < "
(&&.) = unsafeSqlBinOp " AND "
(||.) = unsafeSqlBinOp " OR "
(+.) = unsafeSqlBinOp " + "
(-.) = unsafeSqlBinOp " - "
(/.) = unsafeSqlBinOp " / "
(*.) = unsafeSqlBinOp " * "
random_ = unsafeSqlValue "RANDOM()"
round_ = unsafeSqlFunction "ROUND"
ceiling_ = unsafeSqlFunction "CEILING"
floor_ = unsafeSqlFunction "FLOOR"
sum_ = unsafeSqlFunction "SUM"
min_ = unsafeSqlFunction "MIN"
max_ = unsafeSqlFunction "MAX"
avg_ = unsafeSqlFunction "AVG"
castNum = veryUnsafeCoerceSqlExprValue
castNumM = veryUnsafeCoerceSqlExprValue
coalesce = unsafeSqlFunctionParens "COALESCE"
coalesceDefault exprs = unsafeSqlFunctionParens "COALESCE" . (exprs ++) . return . just
lower_ = unsafeSqlFunction "LOWER"
like = unsafeSqlBinOp " LIKE "
ilike = unsafeSqlBinOp " ILIKE "
(%) = unsafeSqlValue "'%'"
concat_ = unsafeSqlFunction "CONCAT"
(++.) = unsafeSqlBinOp " || "
castString = veryUnsafeCoerceSqlExprValue
subList_select = EList . sub_select
subList_selectDistinct = subList_select . distinct
valList [] = EEmptyList
valList vals = EList $ ERaw Parens $ const ( uncommas ("?" <$ vals)
, map toPersistValue vals )
justList EEmptyList = EEmptyList
justList (EList v) = EList (just v)
v `in_` e = ifNotEmptyList e False $ unsafeSqlBinOp " IN " v (veryUnsafeCoerceSqlExprValueList e)
v `notIn` e = ifNotEmptyList e True $ unsafeSqlBinOp " NOT IN " v (veryUnsafeCoerceSqlExprValueList e)
exists = unsafeSqlFunction "EXISTS " . existsHelper
notExists = unsafeSqlFunction "NOT EXISTS " . existsHelper
set ent upds = Q $ W.tell mempty { sdSetClause = map apply upds }
where
apply (ESet f) = SetClause (f ent)
field =. expr = setAux field (const expr)
field +=. expr = setAux field (\ent -> ent ^. field +. expr)
field -=. expr = setAux field (\ent -> ent ^. field -. expr)
field *=. expr = setAux field (\ent -> ent ^. field *. expr)
field /=. expr = setAux field (\ent -> ent ^. field /. expr)
(<#) _ (ERaw _ f) = EInsert Proxy f
(<#) _ (ECompositeKey _) = unexpectedCompositeKeyError "(<#)"
(EInsert _ f) <&> (ERaw _ g) = EInsert Proxy $ \x ->
let (fb, fv) = f x
(gb, gv) = g x
in (fb <> ", " <> gb, fv ++ gv)
(EInsert _ _) <&> (ECompositeKey _) = unexpectedCompositeKeyError "(<&>)"
case_ = unsafeSqlCase
toBaseId = veryUnsafeCoerceSqlExprValue
instance ToSomeValues SqlExpr (SqlExpr (Value a)) where
toSomeValues a = [SomeValue a]
fieldName :: (PersistEntity val, PersistField typ)
=> IdentInfo -> EntityField val typ -> TLB.Builder
fieldName info = fromDBName info . fieldDB . persistFieldDef
-- FIXME: Composite/non-id pKS not supported on set
setAux :: (PersistEntity val, PersistField typ)
=> EntityField val typ
-> (SqlExpr (Entity val) -> SqlExpr (Value typ))
-> SqlExpr (Update val)
setAux field mkVal = ESet $ \ent -> unsafeSqlBinOp " = " name (mkVal ent)
where name = ERaw Never $ \info -> (fieldName info field, mempty)
sub :: PersistField a => Mode -> SqlQuery (SqlExpr (Value a)) -> SqlExpr (Value a)
sub mode query = ERaw Parens $ \info -> toRawSql mode info query
fromDBName :: IdentInfo -> DBName -> TLB.Builder
fromDBName (conn, _) = TLB.fromText . connEscapeName conn
existsHelper :: SqlQuery () -> SqlExpr (Value Bool)
existsHelper = sub SELECT . (>> return true)
where
true :: SqlExpr (Value Bool)
true = val True
ifNotEmptyList :: SqlExpr (ValueList a) -> Bool -> SqlExpr (Value Bool) -> SqlExpr (Value Bool)
ifNotEmptyList EEmptyList b _ = val b
ifNotEmptyList (EList _) _ x = x
countHelper :: Num a => TLB.Builder -> TLB.Builder -> SqlExpr (Value typ) -> SqlExpr (Value a)
countHelper open close (ERaw _ f) = ERaw Never $ first (\b -> "COUNT" <> open <> parens b <> close) . f
countHelper _ _ (ECompositeKey _) = countRows -- Assumes no NULLs on a PK
----------------------------------------------------------------------
-- | (Internal) Create a case statement.
--
-- Since: 2.1.1
unsafeSqlCase :: PersistField a => [(SqlExpr (Value Bool), SqlExpr (Value a))] -> SqlExpr (Value a) -> SqlExpr (Value a)
unsafeSqlCase when (ERaw p1 f1) = ERaw Never buildCase
where
buildCase :: IdentInfo -> (TLB.Builder, [PersistValue])
buildCase info =
let (b1, vals1) = f1 info
(b2, vals2) = mapWhen when info
in ( "CASE" <> b2 <> " ELSE " <> parensM p1 b1 <> " END", vals2 <> vals1)
mapWhen :: [(SqlExpr (Value Bool), SqlExpr (Value a))] -> IdentInfo -> (TLB.Builder, [PersistValue])
mapWhen [] _ = error "unsafeSqlCase: empty when list."
mapWhen when' info = foldl (foldHelp info) (mempty, mempty) when'
foldHelp :: IdentInfo -> (TLB.Builder, [PersistValue]) -> (SqlExpr (Value Bool), SqlExpr (Value a)) -> (TLB.Builder, [PersistValue])
foldHelp info (b0, vals0) (ERaw p1' f1', ERaw p2 f2) =
let (b1, vals1) = f1' info
(b2, vals2) = f2 info
in ( b0 <> " WHEN " <> parensM p1' b1 <> " THEN " <> parensM p2 b2, vals0 <> vals1 <> vals2 )
foldHelp _ _ _ = unexpectedCompositeKeyError "unsafeSqlCase/foldHelp"
unsafeSqlCase _ (ECompositeKey _) = unexpectedCompositeKeyError "unsafeSqlCase"
-- | (Internal) Create a custom binary operator. You /should/
-- /not/ use this function directly since its type is very
-- general, you should always use it with an explicit type
-- signature. For example:
--
-- @
-- (==.) :: SqlExpr (Value a) -> SqlExpr (Value a) -> SqlExpr (Value Bool)
-- (==.) = unsafeSqlBinOp " = "
-- @
--
-- In the example above, we constraint the arguments to be of the
-- same type and constraint the result to be a boolean value.
unsafeSqlBinOp :: TLB.Builder -> SqlExpr (Value a) -> SqlExpr (Value b) -> SqlExpr (Value c)
unsafeSqlBinOp op (ERaw p1 f1) (ERaw p2 f2) = ERaw Parens f
where
f info = let (b1, vals1) = f1 info
(b2, vals2) = f2 info
in ( parensM p1 b1 <> op <> parensM p2 b2
, vals1 <> vals2 )
unsafeSqlBinOp _ _ _ = unexpectedCompositeKeyError "unsafeSqlBinOp"
{-# INLINE unsafeSqlBinOp #-}
-- | Similar to 'unsafeSqlBinOp', but may also be applied to
-- composite keys. Uses the operator given as the second
-- argument whenever applied to composite keys.
--
-- Usage example:
--
-- @
-- (==.) :: SqlExpr (Value a) -> SqlExpr (Value a) -> SqlExpr (Value Bool)
-- (==.) = unsafeSqlBinOpComposite " = " " AND "
-- @
--
-- Persistent has a hack for implementing composite keys (see
-- 'ECompositeKey' doc for more details), so we're forced to use
-- a hack here as well. We deconstruct 'ERaw' values based on
-- two rules:
--
-- - If it is a single placeholder, then it's assumed to be
-- coming from a 'PersistList' and thus its components are
-- separated so that they may be applied to a composite key.
--
-- - If it is not a single placeholder, then it's assumed to be
-- a foreign (composite or not) key, so we enforce that it has
-- no placeholders and split it on the commas.
unsafeSqlBinOpComposite :: TLB.Builder -> TLB.Builder -> SqlExpr (Value a) -> SqlExpr (Value b) -> SqlExpr (Value c)
unsafeSqlBinOpComposite op _ a@(ERaw _ _) b@(ERaw _ _) = unsafeSqlBinOp op a b
unsafeSqlBinOpComposite op sep a b = ERaw Parens $ compose (listify a) (listify b)
where
listify :: SqlExpr (Value x) -> IdentInfo -> ([TLB.Builder], [PersistValue])
listify (ECompositeKey f) = flip (,) [] . f
listify (ERaw _ f) = deconstruct . f
deconstruct :: (TLB.Builder, [PersistValue]) -> ([TLB.Builder], [PersistValue])
deconstruct ("?", [PersistList vals]) = (replicate (length vals) "?", vals)
deconstruct (b', []) = (TLB.fromLazyText <$> TL.splitOn "," (TLB.toLazyText b'), [])
deconstruct x = err $ "cannot deconstruct " ++ show x ++ "."
compose f1 f2 info
| not (null v1 || null v2) = err' "one side needs to have null placeholders"
| length b1 /= length b2 = err' "mismatching lengths"
| otherwise = (bc, vc)
where
(b1, v1) = f1 info
(b2, v2) = f2 info
bc = intersperseB sep [x <> op <> y | (x, y) <- zip b1 b2]
vc = v1 <> v2
err' = err . (++ (", " ++ show ((b1, v1), (b2, v2))))
err = error . ("unsafeSqlBinOpComposite: " ++)
-- | (Internal) A raw SQL value. The same warning from
-- 'unsafeSqlBinOp' applies to this function as well.
unsafeSqlValue :: TLB.Builder -> SqlExpr (Value a)
unsafeSqlValue v = ERaw Never $ const (v, mempty)
{-# INLINE unsafeSqlValue #-}
-- | (Internal) A raw SQL function. Once again, the same warning
-- from 'unsafeSqlBinOp' applies to this function as well.
unsafeSqlFunction :: UnsafeSqlFunctionArgument a =>
TLB.Builder -> a -> SqlExpr (Value b)
unsafeSqlFunction name arg =
ERaw Never $ \info ->
let (argsTLB, argsVals) =
uncommas' $ map (\(ERaw _ f) -> f info) $ toArgList arg
in (name <> parens argsTLB, argsVals)
-- | (Internal) An unsafe SQL function to extract a subfield from a compound
-- field, e.g. datetime. See 'unsafeSqlBinOp' for warnings.
--
-- Since: 1.3.6.
unsafeSqlExtractSubField :: UnsafeSqlFunctionArgument a =>
TLB.Builder -> a -> SqlExpr (Value b)
unsafeSqlExtractSubField subField arg =
ERaw Never $ \info ->
let (argsTLB, argsVals) =
uncommas' $ map (\(ERaw _ f) -> f info) $ toArgList arg
in ("EXTRACT" <> parens (subField <> " FROM " <> argsTLB), argsVals)
-- | (Internal) A raw SQL function. Preserves parentheses around arguments.
-- See 'unsafeSqlBinOp' for warnings.
unsafeSqlFunctionParens :: UnsafeSqlFunctionArgument a =>
TLB.Builder -> a -> SqlExpr (Value b)
unsafeSqlFunctionParens name arg =
ERaw Never $ \info ->
let (argsTLB, argsVals) =
uncommas' $ map (\(ERaw p f) -> first (parensM p) (f info)) $ toArgList arg
in (name <> parens argsTLB, argsVals)
class UnsafeSqlFunctionArgument a where
toArgList :: a -> [SqlExpr (Value ())]
instance (a ~ Value b) => UnsafeSqlFunctionArgument (SqlExpr a) where
toArgList = (:[]) . veryUnsafeCoerceSqlExprValue
instance UnsafeSqlFunctionArgument a =>
UnsafeSqlFunctionArgument [a] where
toArgList = concatMap toArgList
instance ( UnsafeSqlFunctionArgument a
, UnsafeSqlFunctionArgument b
) => UnsafeSqlFunctionArgument (a, b) where
toArgList (a, b) = toArgList a ++ toArgList b
instance ( UnsafeSqlFunctionArgument a
, UnsafeSqlFunctionArgument b
, UnsafeSqlFunctionArgument c
) => UnsafeSqlFunctionArgument (a, b, c) where
toArgList = toArgList . from3
instance ( UnsafeSqlFunctionArgument a
, UnsafeSqlFunctionArgument b
, UnsafeSqlFunctionArgument c
, UnsafeSqlFunctionArgument d
) => UnsafeSqlFunctionArgument (a, b, c, d) where
toArgList = toArgList . from4
-- | (Internal) Coerce a value's type from 'SqlExpr (Value a)' to
-- 'SqlExpr (Value b)'. You should /not/ use this function
-- unless you know what you're doing!
veryUnsafeCoerceSqlExprValue :: SqlExpr (Value a) -> SqlExpr (Value b)
veryUnsafeCoerceSqlExprValue (ERaw p f) = ERaw p f
veryUnsafeCoerceSqlExprValue (ECompositeKey f) = ECompositeKey f
-- | (Internal) Coerce a value's type from 'SqlExpr (ValueList
-- a)' to 'SqlExpr (Value a)'. Does not work with empty lists.
veryUnsafeCoerceSqlExprValueList :: SqlExpr (ValueList a) -> SqlExpr (Value a)
veryUnsafeCoerceSqlExprValueList (EList v) = v
veryUnsafeCoerceSqlExprValueList EEmptyList =
error "veryUnsafeCoerceSqlExprValueList: empty list."
----------------------------------------------------------------------
-- | (Internal) Execute an @esqueleto@ @SELECT@ 'SqlQuery' inside
-- @persistent@'s 'SqlPersistT' monad.
rawSelectSource :: ( SqlSelect a r
, MonadIO m1
, MonadIO m2 )
=> Mode
-> SqlQuery a
-> SqlReadT m1 (Acquire (C.Source m2 r))
rawSelectSource mode query =
do
conn <- persistBackend <$> R.ask
res <- run conn
return $ (C.$= massage) `fmap` res
where
run conn =
uncurry rawQueryRes $
first builderToText $
toRawSql mode (conn, initialIdentState) query
massage = do
mrow <- C.await
case process <$> mrow of
Just (Right r) -> C.yield r >> massage
Just (Left err) -> liftIO $ throwIO $ PersistMarshalError err
Nothing -> return ()
process = sqlSelectProcessRow
-- | Execute an @esqueleto@ @SELECT@ query inside @persistent@'s
-- 'SqlPersistT' monad and return a 'C.Source' of rows.
selectSource :: ( SqlSelect a r
, MonadResource m )
=> SqlQuery a
-> C.Source (SqlPersistT m) r
selectSource query = do
res <- lift $ rawSelectSource SELECT query
(key, src) <- lift $ allocateAcquire res
src
lift $ release key
-- | Execute an @esqueleto@ @SELECT@ query inside @persistent@'s
-- 'SqlPersistT' monad and return a list of rows.
--
-- We've seen that 'from' has some magic about which kinds of
-- things you may bring into scope. This 'select' function also
-- has some magic for which kinds of things you may bring back to
-- Haskell-land by using @SqlQuery@'s @return@:
--
-- * You may return a @SqlExpr ('Entity' v)@ for an entity @v@
-- (i.e., like the @*@ in SQL), which is then returned to
-- Haskell-land as just @Entity v@.
--
-- * You may return a @SqlExpr (Maybe (Entity v))@ for an entity
-- @v@ that may be @NULL@, which is then returned to
-- Haskell-land as @Maybe (Entity v)@. Used for @OUTER JOIN@s.
--
-- * You may return a @SqlExpr ('Value' t)@ for a value @t@
-- (i.e., a single column), where @t@ is any instance of
-- 'PersistField', which is then returned to Haskell-land as
-- @Value t@. You may use @Value@ to return projections of an
-- @Entity@ (see @('^.')@ and @('?.')@) or to return any other
-- value calculated on the query (e.g., 'countRows' or
-- 'sub_select').
--
-- The @SqlSelect a r@ class has functional dependencies that
-- allow type information to flow both from @a@ to @r@ and
-- vice-versa. This means that you'll almost never have to give
-- any type signatures for @esqueleto@ queries. For example, the
-- query @'select' $ from $ \\p -> return p@ alone is ambiguous, but
-- in the context of
--
-- @
-- do ps <- 'select' $
-- 'from' $ \\p ->
-- return p
-- liftIO $ mapM_ (putStrLn . personName . entityVal) ps
-- @
--
-- we are able to infer from that single @personName . entityVal@
-- function composition that the @p@ inside the query is of type
-- @SqlExpr (Entity Person)@.
select :: ( SqlSelect a r
, MonadIO m )
=> SqlQuery a -> SqlReadT m [r]
select query = do
res <- rawSelectSource SELECT query
conn <- R.ask
liftIO $ with res $ flip R.runReaderT conn . runSource
-- | Execute an @esqueleto@ @SELECT DISTINCT@ query inside
-- @persistent@'s 'SqlPersistT' monad and return a 'C.Source' of
-- rows.
selectDistinctSource
:: ( SqlSelect a r
, MonadResource m )
=> SqlQuery a
-> C.Source (SqlPersistT m) r
selectDistinctSource = selectSource . distinct
{-# DEPRECATED selectDistinctSource "Since 2.2.4: use 'selectSource' and 'distinct'." #-}
-- | Execute an @esqueleto@ @SELECT DISTINCT@ query inside
-- @persistent@'s 'SqlPersistT' monad and return a list of rows.
selectDistinct :: ( SqlSelect a r
, MonadIO m )
=> SqlQuery a -> SqlPersistT m [r]
selectDistinct = select . distinct
{-# DEPRECATED selectDistinct "Since 2.2.4: use 'select' and 'distinct'." #-}
-- | (Internal) Run a 'C.Source' of rows.
runSource :: Monad m =>
C.Source (R.ReaderT backend m) r
-> R.ReaderT backend m [r]
runSource src = src C.$$ CL.consume
----------------------------------------------------------------------
-- | (Internal) Execute an @esqueleto@ statement inside
-- @persistent@'s 'SqlPersistT' monad.
rawEsqueleto :: ( MonadIO m, SqlSelect a r, IsSqlBackend backend)
=> Mode
-> SqlQuery a
-> R.ReaderT backend m Int64
rawEsqueleto mode query = do
conn <- persistBackend <$> R.ask
uncurry rawExecuteCount $
first builderToText $
toRawSql mode (conn, initialIdentState) query
-- | Execute an @esqueleto@ @DELETE@ query inside @persistent@'s
-- 'SqlPersistT' monad. Note that currently there are no type
-- checks for statements that should not appear on a @DELETE@
-- query.
--
-- Example of usage:
--
-- @
-- 'delete' $
-- 'from' $ \\appointment ->
-- 'where_' (appointment '^.' AppointmentDate '<.' 'val' now)
-- @
--
-- Unlike 'select', there is a useful way of using 'delete' that
-- will lead to type ambiguities. If you want to delete all rows
-- (i.e., no 'where_' clause), you'll have to use a type signature:
--
-- @
-- 'delete' $
-- 'from' $ \\(appointment :: 'SqlExpr' ('Entity' Appointment)) ->
-- return ()
-- @
delete :: ( MonadIO m )
=> SqlQuery ()
-> SqlWriteT m ()
delete = void . deleteCount
-- | Same as 'delete', but returns the number of rows affected.
deleteCount :: ( MonadIO m )
=> SqlQuery ()
-> SqlWriteT m Int64
deleteCount = rawEsqueleto DELETE
-- | Execute an @esqueleto@ @UPDATE@ query inside @persistent@'s
-- 'SqlPersistT' monad. Note that currently there are no type
-- checks for statements that should not appear on a @UPDATE@
-- query.
--
-- Example of usage:
--
-- @
-- 'update' $ \\p -> do
-- 'set' p [ PersonAge '=.' 'just' ('val' thisYear) -. p '^.' PersonBorn ]
-- 'where_' $ isNothing (p '^.' PersonAge)
-- @
update :: ( MonadIO m
, SqlEntity val )
=> (SqlExpr (Entity val) -> SqlQuery ())
-> SqlWriteT m ()
update = void . updateCount
-- | Same as 'update', but returns the number of rows affected.
updateCount :: ( MonadIO m
, SqlEntity val )
=> (SqlExpr (Entity val) -> SqlQuery ())
-> SqlWriteT m Int64
updateCount = rawEsqueleto UPDATE . from
----------------------------------------------------------------------
builderToText :: TLB.Builder -> T.Text
builderToText = TL.toStrict . TLB.toLazyTextWith defaultChunkSize
where
defaultChunkSize = 1024 - 32
-- | (Internal) Pretty prints a 'SqlQuery' into a SQL query.
--
-- Note: if you're curious about the SQL query being generated by
-- @esqueleto@, instead of manually using this function (which is
-- possible but tedious), you may just turn on query logging of
-- @persistent@.
toRawSql
:: (IsSqlBackend backend, SqlSelect a r)
=> Mode -> (backend, IdentState) -> SqlQuery a -> (TLB.Builder, [PersistValue])
toRawSql mode (conn, firstIdentState) query =
let ((ret, sd), finalIdentState) =
flip S.runState firstIdentState $
W.runWriterT $
unQ query
SideData distinctClause
fromClauses
setClauses
whereClauses
groupByClause
havingClause
orderByClauses
limitClause
lockingClause = sd
-- Pass the finalIdentState (containing all identifiers
-- that were used) to the subsequent calls. This ensures
-- that no name clashes will occur on subqueries that may
-- appear on the expressions below.
info = (persistBackend conn, finalIdentState)
in mconcat
[ makeInsertInto info mode ret
, makeSelect info mode distinctClause ret
, makeFrom info mode fromClauses
, makeSet info setClauses
, makeWhere info whereClauses
, makeGroupBy info groupByClause
, makeHaving info havingClause
, makeOrderBy info orderByClauses
, makeLimit info limitClause orderByClauses
, makeLocking lockingClause
]
-- | (Internal) Mode of query being converted by 'toRawSql'.
data Mode =
SELECT
| DELETE
| UPDATE
| INSERT_INTO
uncommas :: [TLB.Builder] -> TLB.Builder
uncommas = intersperseB ", "
intersperseB :: TLB.Builder -> [TLB.Builder] -> TLB.Builder
intersperseB a = mconcat . intersperse a . filter (/= mempty)
uncommas' :: Monoid a => [(TLB.Builder, a)] -> (TLB.Builder, a)
uncommas' = (uncommas *** mconcat) . unzip
makeInsertInto :: SqlSelect a r => IdentInfo -> Mode -> a -> (TLB.Builder, [PersistValue])
makeInsertInto info INSERT_INTO ret = sqlInsertInto info ret
makeInsertInto _ _ _ = mempty
makeSelect :: SqlSelect a r => IdentInfo -> Mode -> DistinctClause -> a -> (TLB.Builder, [PersistValue])
makeSelect info mode_ distinctClause ret = process mode_
where
process mode =
case mode of
SELECT -> withCols selectKind
DELETE -> plain "DELETE "
UPDATE -> plain "UPDATE "
INSERT_INTO -> process SELECT
selectKind =
case distinctClause of
DistinctAll -> ("SELECT ", [])
DistinctStandard -> ("SELECT DISTINCT ", [])
DistinctOn exprs -> first (("SELECT DISTINCT ON (" <>) . (<> ") ")) $
uncommas' (processExpr <$> exprs)
where processExpr (EDistinctOn f) = materializeExpr info f
withCols v = v <> sqlSelectCols info ret
plain v = (v, [])
makeFrom :: IdentInfo -> Mode -> [FromClause] -> (TLB.Builder, [PersistValue])
makeFrom _ _ [] = mempty
makeFrom info mode fs = ret
where
ret = case collectOnClauses fs of
Left expr -> throw $ mkExc expr
Right fs' -> keyword $ uncommas' (map (mk Never) fs')
keyword = case mode of
UPDATE -> id
_ -> first ("\nFROM " <>)
mk _ (FromStart i def) = base i def
mk paren (FromJoin lhs kind rhs monClause) =
first (parensM paren) $
mconcat [ mk Never lhs
, (fromKind kind, mempty)
, mk Parens rhs
, maybe mempty makeOnClause monClause
]
mk _ (OnClause _) = error "Esqueleto/Sql/makeFrom: never here (is collectOnClauses working?)"
base ident@(I identText) def =
let db@(DBName dbText) = entityDB def
in ( if dbText == identText
then fromDBName info db
else fromDBName info db <> (" AS " <> useIdent info ident)
, mempty )
fromKind InnerJoinKind = " INNER JOIN "
fromKind CrossJoinKind = " CROSS JOIN "
fromKind LeftOuterJoinKind = " LEFT OUTER JOIN "
fromKind RightOuterJoinKind = " RIGHT OUTER JOIN "
fromKind FullOuterJoinKind = " FULL OUTER JOIN "
makeOnClause (ERaw _ f) = first (" ON " <>) (f info)
makeOnClause (ECompositeKey _) = unexpectedCompositeKeyError "makeFrom/makeOnClause"
mkExc :: SqlExpr (Value Bool) -> OnClauseWithoutMatchingJoinException
mkExc (ERaw _ f) =
OnClauseWithoutMatchingJoinException $
TL.unpack $ TLB.toLazyText $ fst (f info)
mkExc (ECompositeKey _) = unexpectedCompositeKeyError "makeFrom/mkExc"
unexpectedCompositeKeyError :: String -> a
unexpectedCompositeKeyError w = error $ w ++ ": non-id/composite keys not expected here"
makeSet :: IdentInfo -> [SetClause] -> (TLB.Builder, [PersistValue])
makeSet _ [] = mempty
makeSet info os = first ("\nSET " <>) . uncommas' $ concatMap mk os
where
mk (SetClause (ERaw _ f)) = [f info]
mk (SetClause (ECompositeKey _)) = unexpectedCompositeKeyError "makeSet" -- FIXME
makeWhere :: IdentInfo -> WhereClause -> (TLB.Builder, [PersistValue])
makeWhere _ NoWhere = mempty
makeWhere info (Where (ERaw _ f)) = first ("\nWHERE " <>) (f info)
makeWhere _ (Where (ECompositeKey _)) = unexpectedCompositeKeyError "makeWhere"
makeGroupBy :: IdentInfo -> GroupByClause -> (TLB.Builder, [PersistValue])
makeGroupBy _ (GroupBy []) = (mempty, [])
makeGroupBy info (GroupBy fields) = first ("\nGROUP BY " <>) build
where
build :: (TLB.Builder, [PersistValue])
build = uncommas' $ map match fields
match :: SomeValue SqlExpr -> (TLB.Builder, [PersistValue])
match (SomeValue (ERaw _ f)) = f info
match (SomeValue (ECompositeKey f)) = (mconcat $ f info, mempty)
makeHaving :: IdentInfo -> WhereClause -> (TLB.Builder, [PersistValue])
makeHaving _ NoWhere = mempty
makeHaving info (Where (ERaw _ f)) = first ("\nHAVING " <>) (f info)
makeHaving _ (Where (ECompositeKey _)) = unexpectedCompositeKeyError "makeHaving"
-- makeHaving, makeWhere and makeOrderBy
makeOrderBy :: IdentInfo -> [OrderByClause] -> (TLB.Builder, [PersistValue])
makeOrderBy _ [] = mempty
makeOrderBy info os = first ("\nORDER BY " <>) . uncommas' $ concatMap mk os
where
mk :: OrderByClause -> [(TLB.Builder, [PersistValue])]
mk (EOrderBy t (ERaw p f)) = [first ((<> orderByType t) . parensM p) (f info)]
mk (EOrderBy t (ECompositeKey f)) =
let fs = f info
vals = repeat []
in zip (map (<> orderByType t) fs) vals
mk EOrderRandom = [first (<> "RANDOM()") mempty]
orderByType ASC = " ASC"
orderByType DESC = " DESC"
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)
makeLocking :: LockingClause -> (TLB.Builder, [PersistValue])
makeLocking = flip (,) [] . maybe mempty toTLB . getLast
where
toTLB ForUpdate = "\nFOR UPDATE"
toTLB ForShare = "\nFOR SHARE"
toTLB LockInShareMode = "\nLOCK IN SHARE MODE"
parens :: TLB.Builder -> TLB.Builder
parens b = "(" <> (b <> ")")
----------------------------------------------------------------------
-- | (Internal) Class for mapping results coming from 'SqlQuery'
-- into actual results.
--
-- This looks very similar to @RawSql@, and it is! However,
-- there are some crucial differences and ultimately they're
-- different classes.
class SqlSelect a r | a -> r, r -> a where
-- | Creates the variable part of the @SELECT@ query and
-- returns the list of 'PersistValue's that will be given to
-- 'rawQuery'.
sqlSelectCols :: IdentInfo -> a -> (TLB.Builder, [PersistValue])
-- | Number of columns that will be consumed.
sqlSelectColCount :: Proxy a -> Int
-- | Transform a row of the result into the data type.
sqlSelectProcessRow :: [PersistValue] -> Either T.Text r
-- | Create @INSERT INTO@ clause instead.
sqlInsertInto :: IdentInfo -> a -> (TLB.Builder, [PersistValue])
sqlInsertInto = error "Type does not support sqlInsertInto."
-- | @INSERT INTO@ hack.
instance SqlSelect (SqlExpr InsertFinal) InsertFinal where
sqlInsertInto info (EInsertFinal (EInsert p _)) =
let fields = uncommas $
map (fromDBName info . fieldDB) $
entityFields $
entityDef p
table = fromDBName info . entityDB . entityDef $ p
in ("INSERT INTO " <> table <> parens fields <> "\n", [])
sqlSelectCols info (EInsertFinal (EInsert _ f)) = f info
sqlSelectColCount = const 0
sqlSelectProcessRow = const (Right (error msg))
where
msg = "sqlSelectProcessRow/SqlSelect/InsertionFinal: never here"
-- | Not useful for 'select', but used for 'update' and 'delete'.
instance SqlSelect () () where
sqlSelectCols _ _ = ("1", [])
sqlSelectColCount _ = 1
sqlSelectProcessRow _ = Right ()
-- | You may return an 'Entity' from a 'select' query.
instance PersistEntity a => SqlSelect (SqlExpr (Entity a)) (Entity a) where
sqlSelectCols info expr@(EEntity ident) = ret
where
process ed = uncommas $
map ((name <>) . TLB.fromText) $
entityColumnNames ed (fst info)
-- 'name' is the biggest difference between 'RawSql' and
-- 'SqlSelect'. We automatically create names for tables
-- (since it's not the user who's writing the FROM
-- clause), while 'rawSql' assumes that it's just the
-- name of the table (which doesn't allow self-joins, for
-- example).
name = useIdent info ident <> "."
ret = let ed = entityDef $ getEntityVal $ return expr
in (process ed, mempty)
sqlSelectColCount = entityColumnCount . entityDef . getEntityVal
sqlSelectProcessRow = parseEntityValues ed
where ed = entityDef $ getEntityVal (Proxy :: Proxy (SqlExpr (Entity a)))
getEntityVal :: Proxy (SqlExpr (Entity a)) -> Proxy a
getEntityVal = const Proxy
-- | You may return a possibly-@NULL@ 'Entity' from a 'select' query.
instance PersistEntity a => SqlSelect (SqlExpr (Maybe (Entity a))) (Maybe (Entity a)) where
sqlSelectCols info (EMaybe ent) = sqlSelectCols info ent
sqlSelectColCount = sqlSelectColCount . fromEMaybe
where
fromEMaybe :: Proxy (SqlExpr (Maybe e)) -> Proxy (SqlExpr e)
fromEMaybe = const Proxy
sqlSelectProcessRow cols
| all (== PersistNull) cols = return Nothing
| otherwise = Just <$> sqlSelectProcessRow cols
-- | You may return any single value (i.e. a single column) from
-- a 'select' query.
instance PersistField a => SqlSelect (SqlExpr (Value a)) (Value a) where
sqlSelectCols = materializeExpr
sqlSelectColCount = const 1
sqlSelectProcessRow [pv] = Value <$> fromPersistValue pv
sqlSelectProcessRow pvs = Value <$> fromPersistValue (PersistList pvs)
-- | Materialize a @SqlExpr (Value a)@.
materializeExpr :: IdentInfo -> SqlExpr (Value a) -> (TLB.Builder, [PersistValue])
materializeExpr info (ERaw p f) =
let (b, vals) = f info
in (parensM p b, vals)
materializeExpr info (ECompositeKey f) =
let bs = f info
in (uncommas $ map (parensM Parens) bs, [])
-- | You may return tuples (up to 16-tuples) and tuples of tuples
-- from a 'select' query.
instance ( SqlSelect a ra
, SqlSelect b rb
) => SqlSelect (a, b) (ra, rb) where
sqlSelectCols esc (a, b) =
uncommas'
[ sqlSelectCols esc a
, sqlSelectCols esc b
]
sqlSelectColCount = uncurry (+) . (sqlSelectColCount *** sqlSelectColCount) . fromTuple
where
fromTuple :: Proxy (a,b) -> (Proxy a, Proxy b)
fromTuple = const (Proxy, Proxy)
sqlSelectProcessRow =
let x = getType processRow
getType :: SqlSelect a r => (z -> Either y (r,x)) -> Proxy a
getType = const Proxy
colCountFst = sqlSelectColCount x
processRow row =
let (rowFst, rowSnd) = splitAt colCountFst row
in (,) <$> sqlSelectProcessRow rowFst
<*> sqlSelectProcessRow rowSnd
in colCountFst `seq` processRow
-- Avoids recalculating 'colCountFst'.
instance ( SqlSelect a ra
, SqlSelect b rb
, SqlSelect c rc
) => SqlSelect (a, b, c) (ra, rb, rc) where
sqlSelectCols esc (a, b, c) =
uncommas'
[ sqlSelectCols esc a
, sqlSelectCols esc b
, sqlSelectCols esc c
]
sqlSelectColCount = sqlSelectColCount . from3P
sqlSelectProcessRow = fmap to3 . sqlSelectProcessRow
from3P :: Proxy (a,b,c) -> Proxy ((a,b),c)
from3P = const Proxy
from3 :: (a,b,c) -> ((a,b),c)
from3 (a,b,c) = ((a,b),c)
to3 :: ((a,b),c) -> (a,b,c)
to3 ((a,b),c) = (a,b,c)
instance ( SqlSelect a ra
, SqlSelect b rb
, SqlSelect c rc
, SqlSelect d rd
) => SqlSelect (a, b, c, d) (ra, rb, rc, rd) where
sqlSelectCols esc (a, b, c, d) =
uncommas'
[ sqlSelectCols esc a
, sqlSelectCols esc b
, sqlSelectCols esc c
, sqlSelectCols esc d
]
sqlSelectColCount = sqlSelectColCount . from4P
sqlSelectProcessRow = fmap to4 . sqlSelectProcessRow
from4P :: Proxy (a,b,c,d) -> Proxy ((a,b),(c,d))
from4P = const Proxy
from4 :: (a,b,c,d) -> ((a,b),(c,d))
from4 (a,b,c,d) = ((a,b),(c,d))
to4 :: ((a,b),(c,d)) -> (a,b,c,d)
to4 ((a,b),(c,d)) = (a,b,c,d)
instance ( SqlSelect a ra
, SqlSelect b rb
, SqlSelect c rc
, SqlSelect d rd
, SqlSelect e re
) => SqlSelect (a, b, c, d, e) (ra, rb, rc, rd, re) where
sqlSelectCols esc (a, b, c, d, e) =
uncommas'
[ sqlSelectCols esc a
, sqlSelectCols esc b
, sqlSelectCols esc c
, sqlSelectCols esc d
, sqlSelectCols esc e
]
sqlSelectColCount = sqlSelectColCount . from5P
sqlSelectProcessRow = fmap to5 . sqlSelectProcessRow
from5P :: Proxy (a,b,c,d,e) -> Proxy ((a,b),(c,d),e)
from5P = const Proxy
to5 :: ((a,b),(c,d),e) -> (a,b,c,d,e)
to5 ((a,b),(c,d),e) = (a,b,c,d,e)
instance ( SqlSelect a ra
, SqlSelect b rb
, SqlSelect c rc
, SqlSelect d rd
, SqlSelect e re
, SqlSelect f rf
) => SqlSelect (a, b, c, d, e, f) (ra, rb, rc, rd, re, rf) where
sqlSelectCols esc (a, b, c, d, e, f) =
uncommas'
[ sqlSelectCols esc a
, sqlSelectCols esc b
, sqlSelectCols esc c
, sqlSelectCols esc d
, sqlSelectCols esc e
, sqlSelectCols esc f
]
sqlSelectColCount = sqlSelectColCount . from6P
sqlSelectProcessRow = fmap to6 . sqlSelectProcessRow
from6P :: Proxy (a,b,c,d,e,f) -> Proxy ((a,b),(c,d),(e,f))
from6P = const Proxy
to6 :: ((a,b),(c,d),(e,f)) -> (a,b,c,d,e,f)
to6 ((a,b),(c,d),(e,f)) = (a,b,c,d,e,f)
instance ( SqlSelect a ra
, SqlSelect b rb
, SqlSelect c rc
, SqlSelect d rd
, SqlSelect e re
, SqlSelect f rf
, SqlSelect g rg
) => SqlSelect (a, b, c, d, e, f, g) (ra, rb, rc, rd, re, rf, rg) where
sqlSelectCols esc (a, b, c, d, e, f, g) =
uncommas'
[ sqlSelectCols esc a
, sqlSelectCols esc b
, sqlSelectCols esc c
, sqlSelectCols esc d
, sqlSelectCols esc e
, sqlSelectCols esc f
, sqlSelectCols esc g
]
sqlSelectColCount = sqlSelectColCount . from7P
sqlSelectProcessRow = fmap to7 . sqlSelectProcessRow
from7P :: Proxy (a,b,c,d,e,f,g) -> Proxy ((a,b),(c,d),(e,f),g)
from7P = const Proxy
to7 :: ((a,b),(c,d),(e,f),g) -> (a,b,c,d,e,f,g)
to7 ((a,b),(c,d),(e,f),g) = (a,b,c,d,e,f,g)
instance ( SqlSelect a ra
, SqlSelect b rb
, SqlSelect c rc
, SqlSelect d rd
, SqlSelect e re
, SqlSelect f rf
, SqlSelect g rg
, SqlSelect h rh
) => SqlSelect (a, b, c, d, e, f, g, h) (ra, rb, rc, rd, re, rf, rg, rh) where
sqlSelectCols esc (a, b, c, d, e, f, g, h) =
uncommas'
[ sqlSelectCols esc a
, sqlSelectCols esc b
, sqlSelectCols esc c
, sqlSelectCols esc d
, sqlSelectCols esc e
, sqlSelectCols esc f
, sqlSelectCols esc g
, sqlSelectCols esc h
]
sqlSelectColCount = sqlSelectColCount . from8P
sqlSelectProcessRow = fmap to8 . sqlSelectProcessRow
from8P :: Proxy (a,b,c,d,e,f,g,h) -> Proxy ((a,b),(c,d),(e,f),(g,h))
from8P = const Proxy
to8 :: ((a,b),(c,d),(e,f),(g,h)) -> (a,b,c,d,e,f,g,h)
to8 ((a,b),(c,d),(e,f),(g,h)) = (a,b,c,d,e,f,g,h)
instance ( SqlSelect a ra
, SqlSelect b rb
, SqlSelect c rc
, SqlSelect d rd
, SqlSelect e re
, SqlSelect f rf
, SqlSelect g rg
, SqlSelect h rh
, SqlSelect i ri
) => SqlSelect (a, b, c, d, e, f, g, h, i) (ra, rb, rc, rd, re, rf, rg, rh, ri) where
sqlSelectCols esc (a, b, c, d, e, f, g, h, i) =
uncommas'
[ sqlSelectCols esc a
, sqlSelectCols esc b
, sqlSelectCols esc c
, sqlSelectCols esc d
, sqlSelectCols esc e
, sqlSelectCols esc f
, sqlSelectCols esc g
, sqlSelectCols esc h
, sqlSelectCols esc i
]
sqlSelectColCount = sqlSelectColCount . from9P
sqlSelectProcessRow = fmap to9 . sqlSelectProcessRow
from9P :: Proxy (a,b,c,d,e,f,g,h,i) -> Proxy ((a,b),(c,d),(e,f),(g,h),i)
from9P = const Proxy
to9 :: ((a,b),(c,d),(e,f),(g,h),i) -> (a,b,c,d,e,f,g,h,i)
to9 ((a,b),(c,d),(e,f),(g,h),i) = (a,b,c,d,e,f,g,h,i)
instance ( SqlSelect a ra
, SqlSelect b rb
, SqlSelect c rc
, SqlSelect d rd
, SqlSelect e re
, SqlSelect f rf
, SqlSelect g rg
, SqlSelect h rh
, SqlSelect i ri
, SqlSelect j rj
) => SqlSelect (a, b, c, d, e, f, g, h, i, j) (ra, rb, rc, rd, re, rf, rg, rh, ri, rj) where
sqlSelectCols esc (a, b, c, d, e, f, g, h, i, j) =
uncommas'
[ sqlSelectCols esc a
, sqlSelectCols esc b
, sqlSelectCols esc c
, sqlSelectCols esc d
, sqlSelectCols esc e
, sqlSelectCols esc f
, sqlSelectCols esc g
, sqlSelectCols esc h
, sqlSelectCols esc i
, sqlSelectCols esc j
]
sqlSelectColCount = sqlSelectColCount . from10P
sqlSelectProcessRow = fmap to10 . sqlSelectProcessRow
from10P :: Proxy (a,b,c,d,e,f,g,h,i,j) -> Proxy ((a,b),(c,d),(e,f),(g,h),(i,j))
from10P = const Proxy
to10 :: ((a,b),(c,d),(e,f),(g,h),(i,j)) -> (a,b,c,d,e,f,g,h,i,j)
to10 ((a,b),(c,d),(e,f),(g,h),(i,j)) = (a,b,c,d,e,f,g,h,i,j)
instance ( SqlSelect a ra
, SqlSelect b rb
, SqlSelect c rc
, SqlSelect d rd
, SqlSelect e re
, SqlSelect f rf
, SqlSelect g rg
, SqlSelect h rh
, SqlSelect i ri
, SqlSelect j rj
, SqlSelect k rk
) => SqlSelect (a, b, c, d, e, f, g, h, i, j, k) (ra, rb, rc, rd, re, rf, rg, rh, ri, rj, rk) where
sqlSelectCols esc (a, b, c, d, e, f, g, h, i, j, k) =
uncommas'
[ sqlSelectCols esc a
, sqlSelectCols esc b
, sqlSelectCols esc c
, sqlSelectCols esc d
, sqlSelectCols esc e
, sqlSelectCols esc f
, sqlSelectCols esc g
, sqlSelectCols esc h
, sqlSelectCols esc i
, sqlSelectCols esc j
, sqlSelectCols esc k
]
sqlSelectColCount = sqlSelectColCount . from11P
sqlSelectProcessRow = fmap to11 . sqlSelectProcessRow
from11P :: Proxy (a,b,c,d,e,f,g,h,i,j,k) -> Proxy ((a,b),(c,d),(e,f),(g,h),(i,j),k)
from11P = const Proxy
to11 :: ((a,b),(c,d),(e,f),(g,h),(i,j),k) -> (a,b,c,d,e,f,g,h,i,j,k)
to11 ((a,b),(c,d),(e,f),(g,h),(i,j),k) = (a,b,c,d,e,f,g,h,i,j,k)
instance ( SqlSelect a ra
, SqlSelect b rb
, SqlSelect c rc
, SqlSelect d rd
, SqlSelect e re
, SqlSelect f rf
, SqlSelect g rg
, SqlSelect h rh
, SqlSelect i ri
, SqlSelect j rj
, SqlSelect k rk
, SqlSelect l rl
) => SqlSelect (a, b, c, d, e, f, g, h, i, j, k, l) (ra, rb, rc, rd, re, rf, rg, rh, ri, rj, rk, rl) where
sqlSelectCols esc (a, b, c, d, e, f, g, h, i, j, k, l) =
uncommas'
[ sqlSelectCols esc a
, sqlSelectCols esc b
, sqlSelectCols esc c
, sqlSelectCols esc d
, sqlSelectCols esc e
, sqlSelectCols esc f
, sqlSelectCols esc g
, sqlSelectCols esc h
, sqlSelectCols esc i
, sqlSelectCols esc j
, sqlSelectCols esc k
, sqlSelectCols esc l
]
sqlSelectColCount = sqlSelectColCount . from12P
sqlSelectProcessRow = fmap to12 . sqlSelectProcessRow
from12P :: Proxy (a,b,c,d,e,f,g,h,i,j,k,l) -> Proxy ((a,b),(c,d),(e,f),(g,h),(i,j),(k,l))
from12P = const Proxy
to12 :: ((a,b),(c,d),(e,f),(g,h),(i,j),(k,l)) -> (a,b,c,d,e,f,g,h,i,j,k,l)
to12 ((a,b),(c,d),(e,f),(g,h),(i,j),(k,l)) = (a,b,c,d,e,f,g,h,i,j,k,l)
instance ( SqlSelect a ra
, SqlSelect b rb
, SqlSelect c rc
, SqlSelect d rd
, SqlSelect e re
, SqlSelect f rf
, SqlSelect g rg
, SqlSelect h rh
, SqlSelect i ri
, SqlSelect j rj
, SqlSelect k rk
, SqlSelect l rl
, SqlSelect m rm
) => SqlSelect (a, b, c, d, e, f, g, h, i, j, k, l, m) (ra, rb, rc, rd, re, rf, rg, rh, ri, rj, rk, rl, rm) where
sqlSelectCols esc (a, b, c, d, e, f, g, h, i, j, k, l, m) =
uncommas'
[ sqlSelectCols esc a
, sqlSelectCols esc b
, sqlSelectCols esc c
, sqlSelectCols esc d
, sqlSelectCols esc e
, sqlSelectCols esc f
, sqlSelectCols esc g
, sqlSelectCols esc h
, sqlSelectCols esc i
, sqlSelectCols esc j
, sqlSelectCols esc k
, sqlSelectCols esc l
, sqlSelectCols esc m
]
sqlSelectColCount = sqlSelectColCount . from13P
sqlSelectProcessRow = fmap to13 . sqlSelectProcessRow
from13P :: Proxy (a,b,c,d,e,f,g,h,i,j,k,l,m) -> Proxy ((a,b),(c,d),(e,f),(g,h),(i,j),(k,l),m)
from13P = const Proxy
to13 :: ((a,b),(c,d),(e,f),(g,h),(i,j),(k,l),m) -> (a,b,c,d,e,f,g,h,i,j,k,l,m)
to13 ((a,b),(c,d),(e,f),(g,h),(i,j),(k,l),m) = (a,b,c,d,e,f,g,h,i,j,k,l,m)
instance ( SqlSelect a ra
, SqlSelect b rb
, SqlSelect c rc
, SqlSelect d rd
, SqlSelect e re
, SqlSelect f rf
, SqlSelect g rg
, SqlSelect h rh
, SqlSelect i ri
, SqlSelect j rj
, SqlSelect k rk
, SqlSelect l rl
, SqlSelect m rm
, SqlSelect n rn
) => SqlSelect (a, b, c, d, e, f, g, h, i, j, k, l, m, n) (ra, rb, rc, rd, re, rf, rg, rh, ri, rj, rk, rl, rm, rn) where
sqlSelectCols esc (a, b, c, d, e, f, g, h, i, j, k, l, m, n) =
uncommas'
[ sqlSelectCols esc a
, sqlSelectCols esc b
, sqlSelectCols esc c
, sqlSelectCols esc d
, sqlSelectCols esc e
, sqlSelectCols esc f
, sqlSelectCols esc g
, sqlSelectCols esc h
, sqlSelectCols esc i
, sqlSelectCols esc j
, sqlSelectCols esc k
, sqlSelectCols esc l
, sqlSelectCols esc m
, sqlSelectCols esc n
]
sqlSelectColCount = sqlSelectColCount . from14P
sqlSelectProcessRow = fmap to14 . sqlSelectProcessRow
from14P :: Proxy (a,b,c,d,e,f,g,h,i,j,k,l,m,n) -> Proxy ((a,b),(c,d),(e,f),(g,h),(i,j),(k,l),(m,n))
from14P = const Proxy
to14 :: ((a,b),(c,d),(e,f),(g,h),(i,j),(k,l),(m,n)) -> (a,b,c,d,e,f,g,h,i,j,k,l,m,n)
to14 ((a,b),(c,d),(e,f),(g,h),(i,j),(k,l),(m,n)) = (a,b,c,d,e,f,g,h,i,j,k,l,m,n)
instance ( SqlSelect a ra
, SqlSelect b rb
, SqlSelect c rc
, SqlSelect d rd
, SqlSelect e re
, SqlSelect f rf
, SqlSelect g rg
, SqlSelect h rh
, SqlSelect i ri
, SqlSelect j rj
, SqlSelect k rk
, SqlSelect l rl
, SqlSelect m rm
, SqlSelect n rn
, SqlSelect o ro
) => SqlSelect (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) (ra, rb, rc, rd, re, rf, rg, rh, ri, rj, rk, rl, rm, rn, ro) where
sqlSelectCols esc (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) =
uncommas'
[ sqlSelectCols esc a
, sqlSelectCols esc b
, sqlSelectCols esc c
, sqlSelectCols esc d
, sqlSelectCols esc e
, sqlSelectCols esc f
, sqlSelectCols esc g
, sqlSelectCols esc h
, sqlSelectCols esc i
, sqlSelectCols esc j
, sqlSelectCols esc k
, sqlSelectCols esc l
, sqlSelectCols esc m
, sqlSelectCols esc n
, sqlSelectCols esc o
]
sqlSelectColCount = sqlSelectColCount . from15P
sqlSelectProcessRow = fmap to15 . sqlSelectProcessRow
from15P :: Proxy (a,b,c,d,e,f,g,h,i,j,k,l,m,n, o) -> Proxy ((a,b),(c,d),(e,f),(g,h),(i,j),(k,l),(m,n),o)
from15P = const Proxy
to15 :: ((a,b),(c,d),(e,f),(g,h),(i,j),(k,l),(m,n),o) -> (a,b,c,d,e,f,g,h,i,j,k,l,m,n,o)
to15 ((a,b),(c,d),(e,f),(g,h),(i,j),(k,l),(m,n),o) = (a,b,c,d,e,f,g,h,i,j,k,l,m,n,o)
instance ( SqlSelect a ra
, SqlSelect b rb
, SqlSelect c rc
, SqlSelect d rd
, SqlSelect e re
, SqlSelect f rf
, SqlSelect g rg
, SqlSelect h rh
, SqlSelect i ri
, SqlSelect j rj
, SqlSelect k rk
, SqlSelect l rl
, SqlSelect m rm
, SqlSelect n rn
, SqlSelect o ro
, SqlSelect p rp
) => SqlSelect (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p) (ra, rb, rc, rd, re, rf, rg, rh, ri, rj, rk, rl, rm, rn, ro, rp) where
sqlSelectCols esc (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p) =
uncommas'
[ sqlSelectCols esc a
, sqlSelectCols esc b
, sqlSelectCols esc c
, sqlSelectCols esc d
, sqlSelectCols esc e
, sqlSelectCols esc f
, sqlSelectCols esc g
, sqlSelectCols esc h
, sqlSelectCols esc i
, sqlSelectCols esc j
, sqlSelectCols esc k
, sqlSelectCols esc l
, sqlSelectCols esc m
, sqlSelectCols esc n
, sqlSelectCols esc o
, sqlSelectCols esc p
]
sqlSelectColCount = sqlSelectColCount . from16P
sqlSelectProcessRow = fmap to16 . sqlSelectProcessRow
from16P :: Proxy (a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) -> Proxy ((a,b),(c,d),(e,f),(g,h),(i,j),(k,l),(m,n),(o,p))
from16P = const Proxy
to16 :: ((a,b),(c,d),(e,f),(g,h),(i,j),(k,l),(m,n),(o,p)) -> (a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p)
to16 ((a,b),(c,d),(e,f),(g,h),(i,j),(k,l),(m,n),(o,p)) = (a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p)
-- | Insert a 'PersistField' for every selected value.
--
-- /Since: 2.4.2/
insertSelect :: (MonadIO m, PersistEntity a) =>
SqlQuery (SqlExpr (Insertion a)) -> SqlWriteT m ()
insertSelect = void . insertSelectCount
-- | Insert a 'PersistField' for every selected value, return the count afterward
insertSelectCount :: (MonadIO m, PersistEntity a) =>
SqlQuery (SqlExpr (Insertion a)) -> SqlWriteT m Int64
insertSelectCount = rawEsqueleto INSERT_INTO . fmap EInsertFinal
-- | Insert a 'PersistField' for every unique selected value.
insertSelectDistinct :: (MonadIO m, PersistEntity a) =>
SqlQuery (SqlExpr (Insertion a)) -> SqlWriteT m ()
insertSelectDistinct = insertSelect . distinct
{-# DEPRECATED insertSelectDistinct "Since 2.2.4: use 'insertSelect' and 'distinct'." #-}