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Add FROM targets aliasing to avoid conflict in embeds

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This commit is contained in:
steve-chavez
2018-02-21 09:23:08 -05:00
committed by Steve Chávez
parent 8e2a0e05ea
commit ff709a65e5
8 changed files with 154 additions and 34 deletions
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src/PostgREST/DbRequestBuilder.hs
+34 -22
View File
@@ -60,17 +60,21 @@ readRequest maxRows allRels proc apiRequest =
_ -> Nothing
-- Build tree with a Level attribute so when an embed occurs and the parent node has the same name as the child we can differentiate them by having
-- an alias like "node_lvl", this is related to issue #987.
buildReadRequest :: [Tree SelectItem] -> ReadRequest
buildReadRequest fieldTree =
let rootNodeName = if action == ActionRead then rootTableName else sourceCTEName in
foldr treeEntry (Node (Select [] [rootNodeName] [] [] [] allRange, (rootNodeName, Nothing, Nothing, Nothing)) []) fieldTree
let rootLvl = 1
rootNodeName = if action == ActionRead then rootTableName else sourceCTEName in
foldr (treeEntry rootLvl) (Node (Select [] [rootNodeName] [] [] [] allRange, (rootNodeName, Nothing, Nothing, Nothing, rootLvl)) []) fieldTree
where
treeEntry :: Tree SelectItem -> ReadRequest -> ReadRequest
treeEntry (Node fld@((fn, _),_,alias,relationDetail) fldForest) (Node (q, i) rForest) =
treeEntry :: Level -> Tree SelectItem -> ReadRequest -> ReadRequest
treeEntry lvl (Node fld@((fn, _),_,alias,relationDetail) fldForest) (Node (q, i) rForest) =
let nxtLvl = succ lvl in
case fldForest of
[] -> Node (q {select=fld:select q}, i) rForest
_ -> Node (q, i) $
foldr treeEntry (Node (Select [] [fn] [] [] [] allRange, (fn, Nothing, alias, relationDetail)) []) fldForest:rForest
foldr (treeEntry nxtLvl) (Node (Select [] [fn] [] [] [] allRange, (fn, Nothing, alias, relationDetail, nxtLvl)) []) fldForest:rForest
relations :: [Relation]
relations = case action of
@@ -105,9 +109,9 @@ augumentRequestWithJoin schema allRels request =
>>= addJoinConditions schema
addRelations :: Schema -> [Relation] -> Maybe ReadRequest -> ReadRequest -> Either ApiRequestError ReadRequest
addRelations schema allRelations parentNode (Node readNode@(query, (name, _, alias, relationDetail)) forest) =
addRelations schema allRelations parentNode (Node readNode@(query, (name, _, alias, relationDetail, level)) forest) =
case parentNode of
(Just (Node (Select{from=[parentNodeTable]}, (_, _, _, _)) _)) ->
(Just (Node (Select{from=[parentNodeTable]}, _) _)) ->
Node <$> readNode' <*> forest'
where
forest' = updateForest $ hush node'
@@ -190,13 +194,13 @@ addRelations schema allRelations parentNode (Node readNode@(query, (name, _, ali
)
) allRelations
n `colMatches` rc = (toS ("^" <> rc <> "_?(?:|[iI][dD]|[fF][kK])$") :: BS.ByteString) =~ (toS n :: BS.ByteString)
addRel :: (ReadQuery, (NodeName, Maybe Relation, Maybe Alias, Maybe RelationDetail)) -> Relation -> (ReadQuery, (NodeName, Maybe Relation, Maybe Alias, Maybe RelationDetail))
addRel (query', (n, _, a, _)) r = (query' {from=fromRelation}, (n, Just r, a, Nothing))
addRel :: (ReadQuery, (NodeName, Maybe Relation, Maybe Alias, Maybe RelationDetail, Level)) -> Relation -> (ReadQuery, (NodeName, Maybe Relation, Maybe Alias, Maybe RelationDetail, Level))
addRel (query', (n, _, a, _, lvl)) r = (query' {from=fromRelation}, (n, Just r, a, Nothing, lvl))
where fromRelation = map (\t -> if t == n then tableName (relTable r) else t) (from query')
_ -> n' <$> updateForest (Just (n' forest))
where
n' = Node (query, (name, Just r, alias, Nothing))
n' = Node (query, (name, Just r, alias, Nothing, level))
t = Table schema name Nothing True -- !!! TODO find another way to get the table from the query
r = Relation t [] t [] Root Nothing Nothing Nothing
where
@@ -204,7 +208,7 @@ addRelations schema allRelations parentNode (Node readNode@(query, (name, _, ali
updateForest n = mapM (addRelations schema allRelations n) forest
addJoinConditions :: Schema -> ReadRequest -> Either ApiRequestError ReadRequest
addJoinConditions schema (Node node@(query, nodeProps@(_, relation, _, _)) forest) =
addJoinConditions schema (Node node@(query, nodeProps@(_, relation, _, _, lvl)) forest) =
case relation of
Just Relation{relType=Root} -> Node node <$> updatedForest -- this is the root node
Just rel@Relation{relType=Parent} -> Node (augmentQuery rel, nodeProps) <$> updatedForest
@@ -215,23 +219,31 @@ addJoinConditions schema (Node node@(query, nodeProps@(_, relation, _, _)) fores
_ -> Left UnknownRelation
where
updatedForest = mapM (addJoinConditions schema) forest
augmentQuery rel = foldr addJoinCondToReadQuery query (getJoinConds rel)
addJoinCondToReadQuery jc rq@Select{joinConds=jcs} = rq{joinConds=jc:jcs}::ReadQuery
augmentQuery rel = foldr addJoinCondToReadQuery query (getJoinConds lvl rel)
addJoinCondToReadQuery jc rq@Select{joinConds=jcs} = rq{joinConds=jc:jcs}
getJoinConds :: Relation -> [JoinCond]
getJoinConds (Relation t cols ft fcs typ lt lc1 lc2) =
getJoinConds :: Integer -> Relation -> [JoinCond]
getJoinConds level (Relation t cols ft fcs typ lt lc1 lc2) =
case typ of
Child -> zipWith (toJoinCond tN ftN) cols fcs
Parent -> zipWith (toJoinCond tN ftN) cols fcs
Many -> zipWith (toJoinCond tN ltN) cols (fromMaybe [] lc1) ++ zipWith (toJoinCond ftN ltN) fcs (fromMaybe [] lc2)
-- JoinCond needs the Level attr to know the tables aliases
-- The level depends on the sql query structure
-- Child has the embed as:
-- SELECT .., COALESCE(SELECT .. FROM ch AS ch_lvl_2 WHERE ch_lvl_2.col = p_lvl_1.col) FROM p AS p_lvl_1
-- Parent has similar structure regarding the levels
-- Many has the embed as:
-- SELECT .., COALESCE(SELECT .. FROM ch AS ch_lvl_2, gch AS gch_lvl_2 WHERE ch_lvl_2.col = gch_lvl_2.col AND p_lvl_1.acol = ch_lvl_2.acol)
-- FROM p AS p_lvl_1
Child -> zipWith (toJoinCond (tN, level) (ftN, level - 1)) cols fcs
Parent -> zipWith (toJoinCond (tN, level) (ftN, level - 1)) cols fcs
Many -> zipWith (toJoinCond (tN, level) (ltN, level)) cols (fromMaybe [] lc1) ++ zipWith (toJoinCond (ftN, level - 1) (ltN, level)) fcs (fromMaybe [] lc2)
Root -> undefined
where
s = if typ == Parent then "" else tableSchema t
tN = tableName t
ftN = tableName ft
ltN = fromMaybe "" (tableName <$> lt)
toJoinCond :: Text -> Text -> Column -> Column -> JoinCond
toJoinCond tb ftb c fc = JoinCond (QualifiedIdentifier s tb, colName c) (QualifiedIdentifier s ftb, colName fc)
toJoinCond :: (Text, Integer) -> (Text, Integer) -> Column -> Column -> JoinCond
toJoinCond (tb, tLvl) (ftb, fLvl) c fc = JoinCond (QualifiedIdentifier s tb, colName c, tLvl) (QualifiedIdentifier s ftb, colName fc, fLvl)
addFiltersOrdersRanges :: ApiRequest -> Either ApiRequestError (ReadRequest -> ReadRequest)
addFiltersOrdersRanges apiRequest = foldr1 (liftA2 (.)) [
@@ -304,7 +316,7 @@ addProperty f (path, a) (Node rn forest) =
maybeNode = find fnd forst
where
fnd :: ReadRequest -> Bool
fnd (Node (_,(n,_,_,_)) _) = n == name
fnd (Node (_,(n,_,_,_,_)) _) = n == name
mutateRequest :: ApiRequest -> TableName -> [Text] -> [FieldName] -> Either Response MutateRequest
mutateRequest apiRequest tName pkCols fldNames = mapLeft apiRequestError $
@@ -340,7 +352,7 @@ fieldNames (Node (sel, _) forest) =
map (fst . view _1) (select sel) ++ map colName fks
where
fks = concatMap (fromMaybe [] . f) forest
f (Node (_, (_, Just Relation{relFColumns=cols, relType=Parent}, _, _)) _) = Just cols
f (Node (_, (_, Just Relation{relFColumns=cols, relType=Parent}, _, _, _)) _) = Just cols
f _ = Nothing
-- Traditional filters(e.g. id=eq.1) are added as root nodes of the LogicTree
src/PostgREST/QueryBuilder.hs
+14 -10
View File
@@ -1,4 +1,6 @@
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE DuplicateRecordFields #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
{-|
Module : PostgREST.QueryBuilder
@@ -206,7 +208,7 @@ pgFmtLit x =
requestToCountQuery :: Schema -> DbRequest -> SqlQuery
requestToCountQuery _ (DbMutate _) = undefined
requestToCountQuery schema (DbRead (Node (Select _ _ logicForest _ _ _, (mainTbl, _, _, _)) _)) =
requestToCountQuery schema (DbRead (Node (Select{where_=logicForest}, (mainTbl, _, _, _, _)) _)) =
unwords [
"SELECT pg_catalog.count(*)",
"FROM ", fromQi qi,
@@ -216,15 +218,15 @@ requestToCountQuery schema (DbRead (Node (Select _ _ logicForest _ _ _, (mainTbl
qi = removeSourceCTESchema schema mainTbl
requestToQuery :: Schema -> Bool -> DbRequest -> SqlQuery
requestToQuery schema isParent (DbRead (Node (Select colSelects tbls logicForest joinConds_ ordts range, (nodeName, maybeRelation, _, _)) forest)) =
requestToQuery schema isParent (DbRead (Node (Select colSelects tbls logicForest joinConds_ ordts range, (nodeName, maybeRelation, _, _, level)) forest)) =
query
where
mainTbl = fromMaybe nodeName (tableName . relTable <$> maybeRelation)
qi = removeSourceCTESchema schema mainTbl
toQi = removeSourceCTESchema schema
tableAlias tbl = tbl <> "_" <> show level
qi = QualifiedIdentifier "" $ tableAlias mainTbl
query = unwords [
"SELECT " <> intercalate ", " (map (pgFmtSelectItem qi) colSelects ++ selects),
"FROM " <> intercalate ", " (map (fromQi . toQi) tbls),
"FROM " <> intercalate ", " (map (\t -> fromQi (removeSourceCTESchema schema t) <> " AS " <> pgFmtIdent (tableAlias t)) tbls),
unwords joins,
("WHERE " <> intercalate " AND " (map (pgFmtLogicTree qi) logicForest ++ map pgFmtJoinCond joinConds_))
`emptyOnFalse` (null logicForest && null joinConds_),
@@ -234,21 +236,21 @@ requestToQuery schema isParent (DbRead (Node (Select colSelects tbls logicForest
(joins, selects) = foldr getQueryParts ([],[]) forest
getQueryParts :: Tree ReadNode -> ([SqlFragment], [SqlFragment]) -> ([SqlFragment], [SqlFragment])
getQueryParts (Node n@(_, (name, Just Relation{relType=Child,relTable=Table{tableName=table}}, alias, _)) forst) (j,s) = (j,sel:s)
getQueryParts (Node n@(_, (name, Just Relation{relType=Child,relTable=Table{tableName=table}}, alias, _, _)) forst) (j,s) = (j,sel:s)
where
sel = "COALESCE(("
<> "SELECT json_agg(" <> pgFmtIdent table <> ".*) "
<> "FROM (" <> subquery <> ") " <> pgFmtIdent table
<> "), '[]') AS " <> pgFmtIdent (fromMaybe name alias)
where subquery = requestToQuery schema False (DbRead (Node n forst))
getQueryParts (Node n@(_, (name, Just Relation{relType=Parent,relTable=Table{tableName=table}}, alias, _)) forst) (j,s) = (joi:j,sel:s)
getQueryParts (Node n@(_, (name, Just Relation{relType=Parent,relTable=Table{tableName=table}}, alias, _, _)) forst) (j,s) = (joi:j,sel:s)
where
aliasOrName = fromMaybe name alias
localTableName = pgFmtIdent $ table <> "_" <> aliasOrName
sel = "row_to_json(" <> localTableName <> ".*) AS " <> pgFmtIdent aliasOrName
joi = " LEFT JOIN LATERAL( " <> subquery <> " ) AS " <> localTableName <> " ON TRUE "
where subquery = requestToQuery schema True (DbRead (Node n forst))
getQueryParts (Node n@(_, (name, Just Relation{relType=Many,relTable=Table{tableName=table}}, alias, _)) forst) (j,s) = (j,sel:s)
getQueryParts (Node n@(_, (name, Just Relation{relType=Many,relTable=Table{tableName=table}}, alias, _, _)) forst) (j,s) = (j,sel:s)
where
sel = "COALESCE (("
<> "SELECT json_agg(" <> pgFmtIdent table <> ".*) "
@@ -422,8 +424,10 @@ pgFmtFilter table (Filter fld (OpExpr hasNot oper)) = notOp <> " " <> case oper
(find ((==) . toLower $ v) ["null","true","false"])
pgFmtJoinCond :: JoinCond -> SqlFragment
pgFmtJoinCond (JoinCond (qi, cName) (fQi, fcName)) =
pgFmtColumn (removeSourceCTESchema (qiSchema qi) (qiName qi)) cName <> " = " <> pgFmtColumn (removeSourceCTESchema (qiSchema fQi) (qiName fQi)) fcName
pgFmtJoinCond (JoinCond (qi, cName, lvl) (fQi, fcName, fLvl)) =
let qiAlias = QualifiedIdentifier "" (qiName qi <> "_" <> show lvl)
fQiAlias = QualifiedIdentifier "" (qiName fQi <> "_" <> show fLvl) in
pgFmtColumn qiAlias cName <> " = " <> pgFmtColumn fQiAlias fcName
pgFmtLogicTree :: QualifiedIdentifier -> LogicTree -> SqlFragment
pgFmtLogicTree qi (Expr hasNot op forest) = notOp <> " (" <> intercalate (" " <> show op <> " ") (pgFmtLogicTree qi <$> forest) <> ")"
src/PostgREST/Types.hs
+3 -2
View File
@@ -274,13 +274,14 @@ type SelectItem = (Field, Maybe Cast, Maybe Alias, Maybe RelationDetail)
-- | Path of the embedded levels, e.g "clients.projects.name=eq.." gives Path ["clients", "projects"]
type EmbedPath = [Text]
data Filter = Filter { field::Field, opExpr::OpExpr } deriving (Show, Eq)
data JoinCond = JoinCond (QualifiedIdentifier, FieldName) (QualifiedIdentifier, FieldName) deriving (Show, Eq)
data JoinCond = JoinCond (QualifiedIdentifier, FieldName, Level) (QualifiedIdentifier, FieldName, Level) deriving (Show, Eq)
type Level = Integer
data ReadQuery = Select { select::[SelectItem], from::[TableName], where_::[LogicTree], joinConds::[JoinCond], order::[OrderTerm], range_::NonnegRange } deriving (Show, Eq)
data MutateQuery = Insert { in_::TableName, insPkCols::[Text], qPayload::PayloadJSON, onConflict:: Maybe PreferResolution, where_::[LogicTree], returning::[FieldName] }
| Delete { in_::TableName, where_::[LogicTree], returning::[FieldName] }
| Update { in_::TableName, qPayload::PayloadJSON, where_::[LogicTree], returning::[FieldName] } deriving (Show, Eq)
type ReadNode = (ReadQuery, (NodeName, Maybe Relation, Maybe Alias, Maybe RelationDetail))
type ReadNode = (ReadQuery, (NodeName, Maybe Relation, Maybe Alias, Maybe RelationDetail, Level))
type ReadRequest = Tree ReadNode
type MutateRequest = MutateQuery
data DbRequest = DbRead ReadRequest | DbMutate MutateRequest