graphql-engine/server/src-lib/Hasura/RQL/DML/Select.hs
Antoine Leblanc d91029ad51 [gardening] remove all traverse functions from RQL.IR
### Description

This PR removes all `fmapX` and `traverseX` functions from RQL.IR, favouring instead `Functor` and `Traversable` instances throughout the code. This was a relatively straightforward change, except for two small pain points: `AnnSelectG` and `AnnInsert`. Both were parametric over two types `a` and `v`, making it impossible to make them traversable functors... But it turns out that in every single use case, `a ~ f v`. By changing those types to take such an `f :: Type -> Type` as an argument instead of `a :: Type` makes it possible to make them functors.

The only small difference is for `AnnIns`, I had to introduce one `Identity` transformation for one of the `f` parameters. This is relatively straightforward.

### Notes

This PR fixes the most verbose BigQuery hint (`let` instead of `<- pure`).

https://github.com/hasura/graphql-engine-mono/pull/1668

GitOrigin-RevId: e632263a8c559aa04aeae10dcaec915b4a81ad1a
2021-07-08 15:42:53 +00:00

356 lines
13 KiB
Haskell

module Hasura.RQL.DML.Select
( runSelect
)
where
import Hasura.Prelude
import qualified Data.HashMap.Strict as HM
import qualified Data.List.NonEmpty as NE
import qualified Data.Sequence as DS
import qualified Database.PG.Query as Q
import Control.Monad.Trans.Control (MonadBaseControl)
import Data.Aeson.Types
import Data.Text.Extended
import qualified Hasura.Backends.Postgres.SQL.DML as S
import qualified Hasura.Tracing as Tracing
import Hasura.Backends.Postgres.SQL.Types hiding (TableName)
import Hasura.Backends.Postgres.Translate.Select
import Hasura.Base.Error
import Hasura.EncJSON
import Hasura.RQL.DML.Internal
import Hasura.RQL.DML.Types
import Hasura.RQL.IR.OrderBy
import Hasura.RQL.IR.Select
import Hasura.RQL.Types
import Hasura.RQL.Types.Run
import Hasura.SQL.Types
import Hasura.Session
type SelectQExt b = SelectG (ExtCol b) (BoolExp b) Int
-- Columns in RQL
-- This technically doesn't need to be generalized to all backends as
-- it is specific to this module; however the generalization work was
-- already done, and there's no particular reason to force this to be
-- specific.
data ExtCol (b :: BackendType)
= ECSimple !(Column b)
| ECRel !RelName !(Maybe RelName) !(SelectQExt b)
instance Backend b => ToJSON (ExtCol b) where
toJSON (ECSimple s) = toJSON s
toJSON (ECRel rn mrn selq) =
object $ [ "name" .= rn
, "alias" .= mrn
] ++ selectGToPairs selq
instance Backend b => FromJSON (ExtCol b) where
parseJSON v@(Object o) =
ECRel
<$> o .: "name"
<*> o .:? "alias"
<*> parseJSON v
parseJSON v@(String _) =
ECSimple <$> parseJSON v
parseJSON _ =
fail $ mconcat
[ "A column should either be a string or an "
, "object (relationship)"
]
convSelCol
:: (UserInfoM m, QErrM m, TableInfoRM ('Postgres 'Vanilla) m)
=> FieldInfoMap (FieldInfo ('Postgres 'Vanilla))
-> SelPermInfo ('Postgres 'Vanilla)
-> SelCol
-> m [ExtCol ('Postgres 'Vanilla)]
convSelCol _ _ (SCExtSimple cn) =
return [ECSimple cn]
convSelCol fieldInfoMap _ (SCExtRel rn malias selQ) = do
-- Point to the name key
let pgWhenRelErr = "only relationships can be expanded"
relInfo <- withPathK "name" $
askRelType fieldInfoMap rn pgWhenRelErr
let (RelInfo _ _ _ relTab _ _ _) = relInfo
(rfim, rspi) <- fetchRelDet rn relTab
resolvedSelQ <- resolveStar rfim rspi selQ
return [ECRel rn malias resolvedSelQ]
convSelCol fieldInfoMap spi (SCStar wildcard) =
convWildcard fieldInfoMap spi wildcard
convWildcard
:: (UserInfoM m, QErrM m, TableInfoRM ('Postgres 'Vanilla) m)
=> FieldInfoMap (FieldInfo ('Postgres 'Vanilla))
-> SelPermInfo ('Postgres 'Vanilla)
-> Wildcard
-> m [ExtCol ('Postgres 'Vanilla)]
convWildcard fieldInfoMap selPermInfo wildcard =
case wildcard of
Star -> return simpleCols
(StarDot wc) -> (simpleCols ++) <$> (catMaybes <$> relExtCols wc)
where
cols = spiCols selPermInfo
pgCols = map pgiColumn $ getCols fieldInfoMap
relColInfos = getRels fieldInfoMap
simpleCols = map ECSimple $ filter (`HM.member` cols) pgCols
mkRelCol wc relInfo = do
let relName = riName relInfo
relTab = riRTable relInfo
relTabInfo <- fetchRelTabInfo relTab
mRelSelPerm <- askPermInfo' PASelect relTabInfo
forM mRelSelPerm $ \relSelPermInfo -> do
rExtCols <- convWildcard (_tciFieldInfoMap $ _tiCoreInfo relTabInfo) relSelPermInfo wc
return $ ECRel relName Nothing $
SelectG rExtCols Nothing Nothing Nothing Nothing
relExtCols wc = mapM (mkRelCol wc) relColInfos
resolveStar
:: (UserInfoM m, QErrM m, TableInfoRM ('Postgres 'Vanilla) m)
=> FieldInfoMap (FieldInfo ('Postgres 'Vanilla))
-> SelPermInfo ('Postgres 'Vanilla)
-> SelectQ
-> m (SelectQExt ('Postgres 'Vanilla))
resolveStar fim selPermInfo (SelectG selCols mWh mOb mLt mOf) = do
procOverrides <- fmap (concat . catMaybes) $ withPathK "columns" $
indexedForM selCols $ \selCol -> case selCol of
(SCStar _) -> return Nothing
_ -> Just <$> convSelCol fim selPermInfo selCol
everything <- case wildcards of
[] -> return []
_ -> convWildcard fim selPermInfo $ maximum wildcards
let extCols = unionBy equals procOverrides everything
return $ SelectG extCols mWh mOb mLt mOf
where
wildcards = lefts $ map mkEither selCols
mkEither (SCStar wc) = Left wc
mkEither selCol = Right selCol
equals (ECSimple x) (ECSimple y) = x == y
equals (ECRel x _ _) (ECRel y _ _) = x == y
equals _ _ = False
convOrderByElem
:: (UserInfoM m, QErrM m, TableInfoRM ('Postgres 'Vanilla) m)
=> SessVarBldr ('Postgres 'Vanilla) m
-> (FieldInfoMap (FieldInfo ('Postgres 'Vanilla)), SelPermInfo ('Postgres 'Vanilla))
-> OrderByCol
-> m (AnnOrderByElement ('Postgres 'Vanilla) S.SQLExp)
convOrderByElem sessVarBldr (flds, spi) = \case
OCPG fldName -> do
fldInfo <- askFieldInfo flds fldName
case fldInfo of
FIColumn colInfo -> do
checkSelOnCol spi (pgiColumn colInfo)
let ty = pgiType colInfo
if isScalarColumnWhere isGeoType ty
then throw400 UnexpectedPayload $ mconcat
[ fldName <<> " has type 'geometry'"
, " and cannot be used in order_by"
]
else return $ AOCColumn colInfo
FIRelationship _ -> throw400 UnexpectedPayload $ mconcat
[ fldName <<> " is a"
, " relationship and should be expanded"
]
FIComputedField _ -> throw400 UnexpectedPayload $ mconcat
[ fldName <<> " is a"
, " computed field and can't be used in 'order_by'"
]
-- TODO Rakesh (from master)
FIRemoteRelationship {} ->
throw400 UnexpectedPayload (mconcat [ fldName <<> " is a remote field" ])
OCRel fldName rest -> do
fldInfo <- askFieldInfo flds fldName
case fldInfo of
FIColumn _ -> throw400 UnexpectedPayload $ mconcat
[ fldName <<> " is a Postgres column"
, " and cannot be chained further"
]
FIComputedField _ -> throw400 UnexpectedPayload $ mconcat
[ fldName <<> " is a"
, " computed field and can't be used in 'order_by'"
]
FIRelationship relInfo -> do
when (riType relInfo == ArrRel) $
throw400 UnexpectedPayload $ mconcat
[ fldName <<> " is an array relationship"
," and can't be used in 'order_by'"
]
(relFim, relSelPermInfo) <- fetchRelDet (riName relInfo) (riRTable relInfo)
resolvedSelFltr <- convAnnBoolExpPartialSQL sessVarBldr $ spiFilter relSelPermInfo
AOCObjectRelation relInfo resolvedSelFltr <$>
convOrderByElem sessVarBldr (relFim, relSelPermInfo) rest
FIRemoteRelationship {} ->
throw400 UnexpectedPayload (mconcat [ fldName <<> " is a remote field" ])
convSelectQ
:: ( UserInfoM m
, QErrM m
, TableInfoRM ('Postgres 'Vanilla) m
, HasServerConfigCtx m
)
=> TableName ('Postgres 'Vanilla)
-> FieldInfoMap (FieldInfo ('Postgres 'Vanilla)) -- Table information of current table
-> SelPermInfo ('Postgres 'Vanilla) -- Additional select permission info
-> SelectQExt ('Postgres 'Vanilla) -- Given Select Query
-> SessVarBldr ('Postgres 'Vanilla) m
-> ValueParser ('Postgres 'Vanilla) m S.SQLExp
-> m (AnnSimpleSelect ('Postgres 'Vanilla))
convSelectQ table fieldInfoMap selPermInfo selQ sessVarBldr prepValBldr = do
-- Convert where clause
wClause <- forM (sqWhere selQ) $ \boolExp ->
withPathK "where" $
convBoolExp fieldInfoMap selPermInfo boolExp sessVarBldr table prepValBldr
annFlds <- withPathK "columns" $
indexedForM (sqColumns selQ) $ \case
(ECSimple pgCol) -> do
(colInfo, caseBoolExpMaybe) <- convExtSimple fieldInfoMap selPermInfo pgCol
resolvedCaseBoolExp <-
traverse (convAnnColumnCaseBoolExpPartialSQL sessVarBldr) caseBoolExpMaybe
return (fromCol @('Postgres 'Vanilla) pgCol, mkAnnColumnField colInfo resolvedCaseBoolExp Nothing)
(ECRel relName mAlias relSelQ) -> do
annRel <- convExtRel fieldInfoMap relName mAlias
relSelQ sessVarBldr prepValBldr
return ( fromRel $ fromMaybe relName mAlias
, either AFObjectRelation AFArrayRelation annRel
)
annOrdByML <- forM (sqOrderBy selQ) $ \(OrderByExp obItems) ->
withPathK "order_by" $ indexedForM obItems $ mapM $
convOrderByElem sessVarBldr (fieldInfoMap, selPermInfo)
let annOrdByM = NE.nonEmpty =<< annOrdByML
-- validate limit and offset values
withPathK "limit" $ mapM_ onlyPositiveInt mQueryLimit
withPathK "offset" $ mapM_ onlyPositiveInt mQueryOffset
resolvedSelFltr <- convAnnBoolExpPartialSQL sessVarBldr $
spiFilter selPermInfo
let tabFrom = FromTable table
tabPerm = TablePerm resolvedSelFltr mPermLimit
tabArgs = SelectArgs wClause annOrdByM mQueryLimit (fromIntegral <$> mQueryOffset) Nothing
strfyNum <- stringifyNum . _sccSQLGenCtx <$> askServerConfigCtx
return $ AnnSelectG annFlds tabFrom tabPerm tabArgs strfyNum
where
mQueryOffset = sqOffset selQ
mQueryLimit = sqLimit selQ
mPermLimit = spiLimit selPermInfo
convExtSimple
:: (UserInfoM m, QErrM m)
=> FieldInfoMap (FieldInfo ('Postgres 'Vanilla))
-> SelPermInfo ('Postgres 'Vanilla)
-> PGCol
-> m (ColumnInfo ('Postgres 'Vanilla), Maybe (AnnColumnCaseBoolExpPartialSQL ('Postgres 'Vanilla)))
convExtSimple fieldInfoMap selPermInfo pgCol = do
checkSelOnCol selPermInfo pgCol
colInfo <- askColInfo fieldInfoMap pgCol relWhenPGErr
pure (colInfo, join $ HM.lookup pgCol (spiCols selPermInfo))
where
relWhenPGErr = "relationships have to be expanded"
convExtRel
:: ( UserInfoM m
, QErrM m
, TableInfoRM ('Postgres 'Vanilla) m
, HasServerConfigCtx m
)
=> FieldInfoMap (FieldInfo ('Postgres 'Vanilla))
-> RelName
-> Maybe RelName
-> SelectQExt ('Postgres 'Vanilla)
-> SessVarBldr ('Postgres 'Vanilla) m
-> ValueParser ('Postgres 'Vanilla) m S.SQLExp
-> m (Either (ObjectRelationSelect ('Postgres 'Vanilla)) (ArraySelect ('Postgres 'Vanilla)))
convExtRel fieldInfoMap relName mAlias selQ sessVarBldr prepValBldr = do
-- Point to the name key
relInfo <- withPathK "name" $
askRelType fieldInfoMap relName pgWhenRelErr
let (RelInfo _ relTy colMapping relTab _ _ _) = relInfo
(relCIM, relSPI) <- fetchRelDet relName relTab
annSel <- convSelectQ relTab relCIM relSPI selQ sessVarBldr prepValBldr
case relTy of
ObjRel -> do
when misused $ throw400 UnexpectedPayload objRelMisuseMsg
return $ Left $ AnnRelationSelectG (fromMaybe relName mAlias) colMapping $
AnnObjectSelectG (_asnFields annSel) relTab $ _tpFilter $ _asnPerm annSel
ArrRel ->
return $ Right $ ASSimple $ AnnRelationSelectG (fromMaybe relName mAlias)
colMapping annSel
where
pgWhenRelErr = "only relationships can be expanded"
misused =
or [ isJust (sqWhere selQ)
, isJust (sqLimit selQ)
, isJust (sqOffset selQ)
, isJust (sqOrderBy selQ)
]
objRelMisuseMsg =
mconcat [ "when selecting an 'obj_relationship' "
, "'where', 'order_by', 'limit' and 'offset' "
, " can't be used"
]
convSelectQuery
:: ( UserInfoM m
, QErrM m
, TableInfoRM ('Postgres 'Vanilla) m
, HasServerConfigCtx m
)
=> SessVarBldr ('Postgres 'Vanilla) m
-> ValueParser ('Postgres 'Vanilla) m S.SQLExp
-- -> (ColumnType ('Postgres 'Vanilla) -> Value -> m S.SQLExp)
-> SelectQuery
-> m (AnnSimpleSelect ('Postgres 'Vanilla))
convSelectQuery sessVarBldr prepArgBuilder (DMLQuery _ qt selQ) = do
tabInfo <- withPathK "table" $ askTabInfoSource qt
selPermInfo <- askSelPermInfo tabInfo
let fieldInfo = _tciFieldInfoMap $ _tiCoreInfo tabInfo
extSelQ <- resolveStar fieldInfo selPermInfo selQ
validateHeaders $ spiRequiredHeaders selPermInfo
convSelectQ qt fieldInfo selPermInfo extSelQ sessVarBldr prepArgBuilder
selectP2 :: JsonAggSelect -> (AnnSimpleSelect ('Postgres 'Vanilla), DS.Seq Q.PrepArg) -> Q.TxE QErr EncJSON
selectP2 jsonAggSelect (sel, p) =
encJFromBS . runIdentity . Q.getRow
<$> Q.rawQE dmlTxErrorHandler (Q.fromBuilder selectSQL) (toList p) True
where
selectSQL = toSQL $ mkSQLSelect jsonAggSelect sel
phaseOne
:: (QErrM m, UserInfoM m, CacheRM m, HasServerConfigCtx m)
=> SelectQuery -> m (AnnSimpleSelect ('Postgres 'Vanilla), DS.Seq Q.PrepArg)
phaseOne query = do
let sourceName = getSourceDMLQuery query
tableCache :: TableCache ('Postgres 'Vanilla) <- askTableCache sourceName
flip runTableCacheRT (sourceName, tableCache) $ runDMLP1T $
convSelectQuery sessVarFromCurrentSetting (valueParserWithCollectableType binRHSBuilder) query
phaseTwo :: (MonadTx m) => (AnnSimpleSelect ('Postgres 'Vanilla), DS.Seq Q.PrepArg) -> m EncJSON
phaseTwo =
liftTx . selectP2 JASMultipleRows
runSelect
:: ( QErrM m, UserInfoM m, CacheRM m
, HasServerConfigCtx m, MonadIO m, MonadBaseControl IO m
, Tracing.MonadTrace m, MetadataM m
)
=> SelectQuery -> m EncJSON
runSelect q = do
sourceConfig <- askSourceConfig @('Postgres 'Vanilla) (getSourceDMLQuery q)
phaseOne q >>= runQueryLazyTx (_pscExecCtx sourceConfig) Q.ReadOnly . phaseTwo