fix: RPCs not embedding correctly when using overloaded functions for computed relationships

CHANGELOG.md

@@ -17,6 +17,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
  - #2846, Fix error when requesting `Prefer: count=<type>` and doing null filtering on embedded resources - @laurenceisla
  - #2959, Fix setting `default_transaction_isolation` unnecessarily - @steve-chavez
  - #2929, Fix arrow filtering on RPC returning dynamic TABLE with composite type - @steve-chavez
+ - #2963, Fix RPCs not embedding correctly when using overloaded functions for computed relationships - @laurenceisla
 
 ## [11.2.0] - 2023-08-10
 

src/PostgREST/Plan.hs

@@ -380,7 +380,7 @@ addRels schema action allRels parentNode (Node rPlan@ReadPlan{relName,relHint,re
             Relationship{relCardinality=M2M _} -> -- m2m does internal implicit joins that don't need aliasing
               rPlan{from=relForeignTable r, relToParent=Just r, relAggAlias=aggAlias, relJoinConds=getJoinConditions Nothing parentAlias r}
             ComputedRelationship{} ->
-              rPlan{from=relForeignTable r, relToParent=Just r{relTable=maybe (relTable r) (QualifiedIdentifier mempty) parentAlias}, relAggAlias=aggAlias, fromAlias=newAlias}
+              rPlan{from=relForeignTable r, relToParent=Just r{relTableAlias=maybe (relTable r) (QualifiedIdentifier mempty) parentAlias}, relAggAlias=aggAlias, fromAlias=newAlias}
             _ ->
               rPlan{from=relForeignTable r, relToParent=Just r, relAggAlias=aggAlias, fromAlias=newAlias, relJoinConds=getJoinConditions newAlias parentAlias r}
           ) <$> rel

src/PostgREST/Query/QueryBuilder.hs

@@ -242,8 +242,10 @@ getQualifiedIdentifier rel mainQi tblAlias = case rel of
 fromF :: Maybe Relationship -> QualifiedIdentifier -> Maybe Alias -> SQL.Snippet
 fromF rel mainQi tblAlias = "FROM " <>
   (case rel of
-    Just ComputedRelationship{relFunction,relTable} -> fromQi relFunction <> "(" <> pgFmtIdent (qiName relTable) <> ")"
-    _                                               -> fromQi mainQi) <>
+    -- Due to the use of CTEs on RPC, we need to cast the parameter to the table name in case of function overloading.
+    -- See https://github.com/PostgREST/postgrest/issues/2963#issuecomment-1736557386
+    Just ComputedRelationship{relFunction,relTableAlias,relTable} -> fromQi relFunction <> "(" <> pgFmtIdent (qiName relTableAlias) <> "::" <> fromQi relTable <> ")"
+    _                                                             -> fromQi mainQi) <>
   maybe mempty (\a -> " AS " <> pgFmtIdent a) tblAlias <>
   (case rel of
     Just Relationship{relCardinality=M2M Junction{junTable=jt}} -> ", " <> fromQi jt

src/PostgREST/SchemaCache.hs

@@ -882,6 +882,7 @@ allComputedRels =
     (QualifiedIdentifier <$> column HD.text <*> column HD.text) <*>
     (QualifiedIdentifier <$> column HD.text <*> column HD.text) <*>
     (QualifiedIdentifier <$> column HD.text <*> column HD.text) <*>
+    pure (QualifiedIdentifier mempty mempty) <*>
     column HD.bool <*>
     column HD.bool
 

src/PostgREST/SchemaCache/Relationship.hs

@@ -31,6 +31,7 @@ data Relationship = Relationship
   { relFunction     :: QualifiedIdentifier
   , relTable        :: QualifiedIdentifier
   , relForeignTable :: QualifiedIdentifier
+  , relTableAlias   :: QualifiedIdentifier
   , relToOne        :: Bool
   , relIsSelf       :: Bool
   }

test/spec/Feature/Query/ComputedRelsSpec.hs

@@ -192,3 +192,29 @@ spec = describe "computed relationships" $ do
           {"name":"Windows 10","computed_clients":{"name":"Microsoft"}}
         ]}
       ]|] { matchHeaders = [matchContentTypeJson] }
+
+  -- https://github.com/PostgREST/postgrest/issues/2963
+  context "can be defined using overloaded functions" $ do
+    it "tables" $ do
+      get "/items?select=*,computed_rel_overload(*)&limit=1"
+        `shouldRespondWith`
+        [json|
+          [{"id":1,"computed_rel_overload":[{"id":1}]}]
+        |] { matchHeaders = [matchContentTypeJson] }
+      get "/items2?select=*,computed_rel_overload(*)&limit=1"
+        `shouldRespondWith`
+        [json|
+          [{"id":1,"computed_rel_overload":[{"id":1},{"id":2}]}]
+        |] { matchHeaders = [matchContentTypeJson] }
+
+    it "rpc" $ do
+      get "/rpc/search?id=1&select=*,computed_rel_overload(*)"
+        `shouldRespondWith`
+        [json|
+          [{"id":1,"computed_rel_overload":[{"id":1}]}]
+        |] { matchHeaders = [matchContentTypeJson] }
+      get "/rpc/search2?id=1&select=*,computed_rel_overload(*)"
+        `shouldRespondWith`
+        [json|
+          [{"id":1,"computed_rel_overload":[{"id":1},{"id":2}]}]
+        |] { matchHeaders = [matchContentTypeJson] }

test/spec/fixtures/schema.sql

@@ -3456,3 +3456,18 @@ returns table(id int, val complex) as $$
   union
   select 3, row(0.3, 0.7)::complex as val;
 $$ language sql;
+
+create function computed_rel_overload(items) returns setof items2 as $$
+  select * from items2 limit 1
+$$ language sql;
+
+create function computed_rel_overload(items2) returns setof items2 as $$
+  select * from items2 limit 2
+$$ language sql;
+
+create function search2(id bigint) returns setof items2
+language plpgsql
+stable
+as $$ begin
+  return query select items2.id from items2 where items2.id=search2.id;
+end$$;