refactor: all aliasing in addRels

src/PostgREST/Plan.hs

@@ -107,7 +107,7 @@ initReadRequest qi@QualifiedIdentifier{..} =
   foldr (treeEntry rootDepth) $ Node defReadPlan{from=qi, relName=qiName, depth=rootDepth} []
   where
     rootDepth = 0
-    defReadPlan = ReadPlan [] (QualifiedIdentifier mempty mempty) Nothing [] [] allRange mempty Nothing [] Nothing Nothing Nothing rootDepth
+    defReadPlan = ReadPlan [] (QualifiedIdentifier mempty mempty) Nothing [] [] allRange mempty Nothing [] Nothing mempty Nothing Nothing rootDepth
     treeEntry :: Depth -> Tree SelectItem -> ReadPlanTree -> ReadPlanTree
     treeEntry depth (Node fld@((fldName, _),_,alias, hint, joinType) fldForest) (Node q rForest) =
       let nxtDepth = succ depth in
@@ -128,17 +128,18 @@ treeRestrictRange maxRows _ request = pure $ nodeRestrictRange maxRows <$> reque
 
 -- add relationships to the nodes of the tree by traversing the forest while keeping track of the parentNode, also adds aliasing
 addRels :: Schema -> Action -> RelationshipsMap -> Maybe ReadPlanTree -> ReadPlanTree -> Either ApiRequestError ReadPlanTree
-addRels schema action allRels parentNode (Node rPlan@ReadPlan{relName,relHint,depth} forest) =
+addRels schema action allRels parentNode (Node rPlan@ReadPlan{relName,relHint,relAlias,depth} forest) =
   case parentNode of
     Just (Node ReadPlan{from=parentNodeQi, fromAlias} _) ->
       let
         newReadPlan = (\r ->
-          let newAlias = Just (qiName (relForeignTable r) <> "_" <> show depth) in
+          let newAlias = Just (qiName (relForeignTable r) <> "_" <> show depth)
+              aggAlias = qiName (relTable r) <> "_" <> fromMaybe relName relAlias <> "_" <> show depth in
           case r of
             Relationship{relCardinality=M2M _} ->
-              rPlan{from=relForeignTable r, relToParent=Just r, relJoinConds=getJoinConditions Nothing fromAlias r}
+              rPlan{from=relForeignTable r, relToParent=Just r, relAggAlias=aggAlias, relJoinConds=getJoinConditions Nothing fromAlias r}
             _ ->
-              rPlan{from=relForeignTable r, relToParent=Just r, fromAlias=newAlias, relJoinConds=getJoinConditions newAlias fromAlias r}
+              rPlan{from=relForeignTable r, relToParent=Just r, relAggAlias=aggAlias, fromAlias=newAlias, relJoinConds=getJoinConditions newAlias fromAlias r}
           ) <$> rel
         origin = if depth == 1 -- Only on depth 1 we check if the root(depth 0) has an alias so the sourceCTEName alias can be found as a relationship
           then fromMaybe (qiName parentNodeQi) fromAlias

src/PostgREST/Plan/ReadPlan.hs

@@ -39,6 +39,7 @@ data ReadPlan = ReadPlan
   , relToParent  :: Maybe Relationship
   , relJoinConds :: [JoinCondition]
   , relAlias     :: Maybe Alias
+  , relAggAlias  :: Alias
   , relHint      :: Maybe Hint
   , relJoinType  :: Maybe JoinType
   , depth        :: Depth

src/PostgREST/Query/QueryBuilder.hs

@@ -56,11 +56,11 @@ readPlanToQuery (Node ReadPlan{select,from=mainQi,fromAlias,where_=logicForest,o
 
 getSelectsJoins :: ReadPlanTree -> ([SQL.Snippet], [SQL.Snippet]) -> ([SQL.Snippet], [SQL.Snippet])
 getSelectsJoins (Node ReadPlan{relToParent=Nothing} _) _ = ([], [])
-getSelectsJoins rr@(Node ReadPlan{relName, relToParent=Just rel, relAlias, relJoinType=joinType, depth} _) (selects,joins) =
+getSelectsJoins rr@(Node ReadPlan{relName, relToParent=Just rel, relAggAlias, relAlias, relJoinType=joinType} _) (selects,joins) =
   let
     subquery = readPlanToQuery rr
-    aliasOrName = fromMaybe relName relAlias
-    localTableName = pgFmtIdent $ qiName (relTable rel) <> "_" <> aliasOrName <> "_" <> show depth
+    aliasOrName = pgFmtIdent $ fromMaybe relName relAlias
+    aggAlias = pgFmtIdent relAggAlias
     correlatedSubquery sub al cond =
       (if joinType == Just JTInner then "INNER" else "LEFT") <> " JOIN LATERAL ( " <> sub <> " ) AS " <> SQL.sql al <> " ON " <> cond
     isToOne = case rel of
@@ -70,14 +70,14 @@ getSelectsJoins rr@(Node ReadPlan{relName, relToParent=Just rel, relAlias, relJo
       _                                    -> False
     (sel, joi) = if isToOne
       then
-        ( SQL.sql ("row_to_json(" <> localTableName <> ".*) AS " <> pgFmtIdent aliasOrName)
-        , correlatedSubquery subquery localTableName "TRUE")
+        ( SQL.sql ("row_to_json(" <> aggAlias <> ".*) AS " <> aliasOrName)
+        , correlatedSubquery subquery aggAlias "TRUE")
       else
-        ( SQL.sql $ "COALESCE( " <> localTableName <> "." <> localTableName <> ", '[]') AS " <> pgFmtIdent aliasOrName
+        ( SQL.sql $ "COALESCE( " <> aggAlias <> "." <> aggAlias <> ", '[]') AS " <> aliasOrName
         , correlatedSubquery (
-            "SELECT json_agg(" <> SQL.sql localTableName <> ") AS " <> SQL.sql localTableName <>
-            "FROM (" <> subquery <> " ) AS " <> SQL.sql localTableName
-          ) localTableName $ if joinType == Just JTInner then SQL.sql localTableName <> " IS NOT NULL" else "TRUE")
+            "SELECT json_agg(" <> SQL.sql aggAlias <> ") AS " <> SQL.sql aggAlias <>
+            "FROM (" <> subquery <> " ) AS " <> SQL.sql aggAlias
+          ) aggAlias $ if joinType == Just JTInner then SQL.sql aggAlias <> " IS NOT NULL" else "TRUE")
   in
   (sel:selects, joi:joins)