graphql-engine/server/src-lib/Hasura/GraphQL/Resolve/Mutation.hs
Vamshi Surabhi 32ae105279 improved sql generation for select queries (closes #6, #121, #278) (#643)
Better SQL generation for select queries (the query plans will be the same but much more readable). This closes some long standing issues (#6, #121, #278).
2018-10-05 14:26:47 +05:30

251 lines
8.8 KiB
Haskell

{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE MultiWayIf #-}
{-# LANGUAGE NoImplicitPrelude #-}
{-# LANGUAGE OverloadedStrings #-}
module Hasura.GraphQL.Resolve.Mutation
( convertUpdate
, convertInsert
, convertDelete
) where
import Hasura.Prelude
import qualified Data.HashMap.Strict as Map
import qualified Data.HashSet as Set
import qualified Language.GraphQL.Draft.Syntax as G
import qualified Hasura.RQL.DML.Delete as RD
import qualified Hasura.RQL.DML.Insert as RI
import qualified Hasura.RQL.DML.Returning as RR
import qualified Hasura.RQL.DML.Select as RS
import qualified Hasura.RQL.DML.Update as RU
import qualified Hasura.SQL.DML as S
import Hasura.GraphQL.Resolve.BoolExp
import Hasura.GraphQL.Resolve.Context
import Hasura.GraphQL.Resolve.InputValue
import Hasura.GraphQL.Resolve.Select (fromSelSet)
import Hasura.GraphQL.Validate.Field
import Hasura.GraphQL.Validate.Types
import Hasura.RQL.Types
import Hasura.SQL.Types
import Hasura.SQL.Value
withSelSet :: (Monad m) => SelSet -> (Field -> m a) -> m [(Text, a)]
withSelSet selSet f =
forM (toList selSet) $ \fld -> do
res <- f fld
return (G.unName $ G.unAlias $ _fAlias fld, res)
convertReturning
:: QualifiedTable -> G.NamedType -> SelSet -> Convert RS.AnnSel
convertReturning qt ty selSet = do
annFlds <- fromSelSet ty selSet
return $ RS.AnnSel annFlds qt (Just frmItem)
(S.BELit True) Nothing RS.noTableArgs
where
frmItem = S.FIIden $ RR.qualTableToAliasIden qt
convertMutResp
:: QualifiedTable -> G.NamedType -> SelSet -> Convert RR.MutFlds
convertMutResp qt ty selSet =
withSelSet selSet $ \fld ->
case _fName fld of
"__typename" -> return $ RR.MExp $ G.unName $ G.unNamedType ty
"affected_rows" -> return RR.MCount
_ -> fmap RR.MRet $ convertReturning qt (_fType fld) $ _fSelSet fld
convertRowObj
:: (MonadError QErr m, MonadState PrepArgs m)
=> AnnGValue
-> m [(PGCol, S.SQLExp)]
convertRowObj val =
flip withObject val $ \_ obj -> forM (Map.toList obj) $ \(k, v) -> do
prepExpM <- asPGColValM v >>= mapM prepare
let prepExp = fromMaybe (S.SEUnsafe "NULL") prepExpM
return (PGCol $ G.unName k, prepExp)
mkConflictClause :: RI.ConflictCtx -> RI.ConflictClauseP1
mkConflictClause (RI.CCDoNothing constrM) =
RI.CP1DoNothing $ fmap RI.Constraint constrM
mkConflictClause (RI.CCUpdate constr updCols) =
RI.CP1Update (RI.Constraint constr) updCols
parseAction
:: (MonadError QErr m)
=> AnnGObject -> m (Maybe ConflictAction)
parseAction obj =
mapM parseVal $ Map.lookup "action" obj
where
parseVal val = do
(enumTy, enumVal) <- asEnumVal val
withPathK "action" $ case G.unName $ G.unEnumValue enumVal of
"ignore" -> return CAIgnore
"update" -> return CAUpdate
_ -> throw500 $
"only \"ignore\" and \"updated\" allowed for enum type "
<> showNamedTy enumTy
parseConstraint
:: (MonadError QErr m)
=> AnnGObject -> m ConstraintName
parseConstraint obj = do
v <- onNothing (Map.lookup "constraint" obj) $ throw500
"\"constraint\" is expected, but not found"
parseVal v
where
parseVal v = do
(_, enumVal) <- asEnumVal v
return $ ConstraintName $ G.unName $ G.unEnumValue enumVal
parseUpdCols
:: (MonadError QErr m)
=> AnnGObject -> m (Maybe [PGCol])
parseUpdCols obj =
mapM parseVal $ Map.lookup "update_columns" obj
where
parseVal val = flip withArray val $ \_ enumVals ->
forM enumVals $ \eVal -> do
(_, v) <- asEnumVal eVal
return $ PGCol $ G.unName $ G.unEnumValue v
parseOnConflict
:: (MonadError QErr m)
=> [PGCol] -> AnnGValue -> m RI.ConflictCtx
parseOnConflict inpCols val =
flip withObject val $ \_ obj -> do
actionM <- parseAction obj
constraint <- parseConstraint obj
updColsM <- parseUpdCols obj
-- consider "action" if "update_columns" is not mentioned
return $ case (updColsM, actionM) of
(Just [], _) -> RI.CCDoNothing $ Just constraint
(Just cols, _) -> RI.CCUpdate constraint cols
(Nothing, Just CAIgnore) -> RI.CCDoNothing $ Just constraint
(Nothing, _) -> RI.CCUpdate constraint inpCols
convertInsert
:: RoleName
-> (QualifiedTable, QualifiedTable) -- table, view
-> [PGCol] -- all the columns in this table
-> Field -- the mutation field
-> Convert RespTx
convertInsert role (tn, vn) tableCols fld = do
insTuples <- withArg arguments "objects" asRowExps
let inpCols = Set.toList $ Set.fromList $ concatMap fst insTuples
conflictCtxM <- withArgM arguments "on_conflict" $ parseOnConflict inpCols
let onConflictM = fmap mkConflictClause conflictCtxM
mutFlds <- convertMutResp tn (_fType fld) $ _fSelSet fld
args <- get
let rows = map snd insTuples
p1Query = RI.InsertQueryP1 tn vn tableCols rows onConflictM mutFlds
p1 = (p1Query, args)
return $
bool (RI.nonAdminInsert p1) (RI.insertP2 p1) $ isAdmin role
where
arguments = _fArguments fld
asRowExps = withArray (const $ mapM rowExpWithDefaults)
rowExpWithDefaults val = do
givenCols <- convertRowObj val
let inpCols = map fst givenCols
sqlExps = Map.elems $ Map.union (Map.fromList givenCols) defVals
return (inpCols, sqlExps)
defVals = Map.fromList $ zip tableCols (repeat $ S.SEUnsafe "DEFAULT")
type ApplySQLOp = (PGCol, S.SQLExp) -> S.SQLExp
rhsExpOp :: S.SQLOp -> S.AnnType -> ApplySQLOp
rhsExpOp op annTy (col, e) =
S.mkSQLOpExp op (S.SEIden $ toIden col) annExp
where
annExp = S.SETyAnn e annTy
lhsExpOp :: S.SQLOp -> S.AnnType -> ApplySQLOp
lhsExpOp op annTy (col, e) =
S.mkSQLOpExp op annExp $ S.SEIden $ toIden col
where
annExp = S.SETyAnn e annTy
convObjWithOp
:: (MonadError QErr m)
=> ApplySQLOp -> AnnGValue -> m [(PGCol, S.SQLExp)]
convObjWithOp opFn val =
flip withObject val $ \_ obj -> forM (Map.toList obj) $ \(k, v) -> do
(_, colVal) <- asPGColVal v
let pgCol = PGCol $ G.unName k
encVal = txtEncoder colVal
sqlExp = opFn (pgCol, encVal)
return (pgCol, sqlExp)
convDeleteAtPathObj
:: (MonadError QErr m)
=> AnnGValue -> m [(PGCol, S.SQLExp)]
convDeleteAtPathObj val =
flip withObject val $ \_ obj -> forM (Map.toList obj) $ \(k, v) -> do
vals <- flip withArray v $ \_ annVals -> mapM asPGColVal annVals
let valExps = map (txtEncoder . snd) vals
pgCol = PGCol $ G.unName k
annEncVal = S.SETyAnn (S.SEArray valExps) S.textArrType
sqlExp = S.SEOpApp S.jsonbDeleteAtPathOp
[S.SEIden $ toIden pgCol, annEncVal]
return (pgCol, sqlExp)
convertUpdate
:: QualifiedTable -- table
-> S.BoolExp -- the filter expression
-> Field -- the mutation field
-> Convert RespTx
convertUpdate tn filterExp fld = do
-- a set expression is same as a row object
setExpM <- withArgM args "_set" convertRowObj
-- where bool expression to filter column
whereExp <- withArg args "where" $ convertBoolExp tn
-- increment operator on integer columns
incExpM <- withArgM args "_inc" $
convObjWithOp $ rhsExpOp S.incOp S.intType
-- append jsonb value
appendExpM <- withArgM args "_append" $
convObjWithOp $ rhsExpOp S.jsonbConcatOp S.jsonbType
-- prepend jsonb value
prependExpM <- withArgM args "_prepend" $
convObjWithOp $ lhsExpOp S.jsonbConcatOp S.jsonbType
-- delete a key in jsonb object
deleteKeyExpM <- withArgM args "_delete_key" $
convObjWithOp $ rhsExpOp S.jsonbDeleteOp S.textType
-- delete an element in jsonb array
deleteElemExpM <- withArgM args "_delete_elem" $
convObjWithOp $ rhsExpOp S.jsonbDeleteOp S.intType
-- delete at path in jsonb value
deleteAtPathExpM <- withArgM args "_delete_at_path" convDeleteAtPathObj
mutFlds <- convertMutResp tn (_fType fld) $ _fSelSet fld
prepArgs <- get
let updExpsM = [ setExpM, incExpM, appendExpM, prependExpM
, deleteKeyExpM, deleteElemExpM, deleteAtPathExpM
]
updExp = concat $ catMaybes updExpsM
-- atleast one of update operators is expected
unless (any isJust updExpsM) $ throwVE $
"atleast any one of _set, _inc, _append, _prepend, _delete_key, _delete_elem and "
<> " _delete_at_path operator is expected"
let p1 = RU.UpdateQueryP1 tn updExp (filterExp, whereExp) mutFlds
return $ RU.updateP2 (p1, prepArgs)
where
args = _fArguments fld
convertDelete
:: QualifiedTable -- table
-> S.BoolExp -- the filter expression
-> Field -- the mutation field
-> Convert RespTx
convertDelete tn filterExp fld = do
whereExp <- withArg (_fArguments fld) "where" $ convertBoolExp tn
mutFlds <- convertMutResp tn (_fType fld) $ _fSelSet fld
args <- get
let p1 = RD.DeleteQueryP1 tn (filterExp, whereExp) mutFlds
return $ RD.deleteP2 (p1, args)