fix: handle queries on non-existing table gracefully

* Add new `TableNotFound` error with error code PGRST205

* Closes #3697, #3602.

CHANGELOG.md

@@ -25,6 +25,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
    + Fixed `"column <json_aggregate>.<alias> does not exist"` error when selecting `?select=...table(aias:count())`
  - #3727, Clarify "listening" logs - @steve-chavez
  - #3795, Clarify `Accept: vnd.pgrst.object` error message - @steve-chavez
+ - #3697, #3602, Handle queries on non-existing table gracefully - @taimoorzaeem
 
 ### Changed
 
@@ -37,6 +38,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
    - Previously, this would silently return 200 - OK on the root endpoint, but don't provide any usable endpoints.
  - #3757, Remove support for `Prefer: params=single-object` - @joelonsql
    + This preference was deprecated in favor of Functions with an array of JSON objects
+ - #3697, #3602, Querying non-existent table now returns `PGRST205` error instead of empty json - @taimoorzaeem
 
 ## [12.2.7] - 2025-02-03
 

docs/references/errors.rst

@@ -294,6 +294,10 @@ Related to a :ref:`schema_cache`. Most of the time, these errors are solved by :
 |               |             | in the ``columns`` query parameter is not found.            |
 | PGRST204      |             |                                                             |
 +---------------+-------------+-------------------------------------------------------------+
+| .. _pgrst205: | 404         | Caused when the :ref:`table specified <tables_views>` in    |
+|               |             | the URI is not found.                                       |
+| PGRST205      |             |                                                             |
++---------------+-------------+-------------------------------------------------------------+
 
 .. _pgrst3**:
 

src/PostgREST/ApiRequest/Types.hs

@@ -42,6 +42,7 @@ import PostgREST.SchemaCache.Identifiers  (FieldName,
 import PostgREST.SchemaCache.Relationship (Relationship,
                                            RelationshipsMap)
 import PostgREST.SchemaCache.Routine      (Routine (..))
+import PostgREST.SchemaCache.Table        (Table)
 
 import Protolude
 
@@ -92,6 +93,7 @@ data ApiRequestError
   | UnacceptableSchema [Text]
   | UnsupportedMethod ByteString
   | ColumnNotFound Text Text
+  | TableNotFound Text Text [Table]
   | GucHeadersError
   | GucStatusError
   | OffLimitsChangesError Int64 Integer

src/PostgREST/Error.hs

@@ -47,6 +47,7 @@ import PostgREST.SchemaCache.Relationship (Cardinality (..),
                                            RelationshipsMap)
 import PostgREST.SchemaCache.Routine      (Routine (..),
                                            RoutineParam (..))
+import PostgREST.SchemaCache.Table        (Table (..))
 import Protolude
 
 
@@ -86,6 +87,7 @@ instance PgrstError ApiRequestError where
   status UnsupportedMethod{}         = HTTP.status405
   status LimitNoOrderError           = HTTP.status400
   status ColumnNotFound{}            = HTTP.status400
+  status TableNotFound{}             = HTTP.status404
   status GucHeadersError             = HTTP.status500
   status GucStatusError              = HTTP.status500
   status OffLimitsChangesError{}     = HTTP.status400
@@ -253,6 +255,12 @@ instance JSON.ToJSON ApiRequestError where
   toJSON (ColumnNotFound relName colName) = toJsonPgrstError
     SchemaCacheErrorCode04 ("Could not find the '" <> colName <> "' column of '" <> relName <> "' in the schema cache") Nothing Nothing
 
+  toJSON (TableNotFound schemaName relName tbls) = toJsonPgrstError
+    SchemaCacheErrorCode05
+    ("Could not find relation '" <> schemaName <> "." <> relName <> "' in the schema cache")
+    Nothing
+    (JSON.String <$> tableNotFoundHint schemaName relName tbls)
+
 -- |
 -- If no relationship is found then:
 --
@@ -350,6 +358,16 @@ noRpcHint schema procName params allProcs overloadedProcs =
       | null overloadedProcs = Fuzzy.getOne fuzzySetOfProcs procName
       | otherwise            = (procName <>) <$> Fuzzy.getOne fuzzySetOfParams (listToText params)
 
+-- |
+-- Do a fuzzy search in all tables in the same schema and return closest result
+tableNotFoundHint :: Text -> Text -> [Table] -> Maybe Text
+tableNotFoundHint schema tblName tblList
+  = fmap (\tbl -> "Perhaps you meant the relation '" <> schema <> "." <> tbl <> "'") perhapsTable
+    where
+      perhapsTable = Fuzzy.getOne fuzzyTableSet tblName
+      fuzzyTableSet = Fuzzy.fromList [ tableName tbl | tbl <- tblList, tableSchema tbl == schema]
+
+
 compressedRel :: Relationship -> JSON.Value
 -- An ambiguousness error cannot happen for computed relationships TODO refactor so this mempty is not needed
 compressedRel ComputedRelationship{} = JSON.object mempty
@@ -640,6 +658,7 @@ data ErrorCode
   | SchemaCacheErrorCode02
   | SchemaCacheErrorCode03
   | SchemaCacheErrorCode04
+  | SchemaCacheErrorCode05
   -- JWT authentication errors
   | JWTErrorCode00
   | JWTErrorCode01
@@ -689,6 +708,7 @@ buildErrorCode code = case code of
   SchemaCacheErrorCode02 -> "PGRST202"
   SchemaCacheErrorCode03 -> "PGRST203"
   SchemaCacheErrorCode04 -> "PGRST204"
+  SchemaCacheErrorCode05 -> "PGRST205"
 
   JWTErrorCode00         -> "PGRST300"
   JWTErrorCode01         -> "PGRST301"

src/PostgREST/Plan.hs

@@ -152,14 +152,14 @@ dbActionPlan dbAct conf apiReq sCache = case dbAct of
 
 wrappedReadPlan :: QualifiedIdentifier -> AppConfig -> SchemaCache -> ApiRequest -> Bool -> Either Error CrudPlan
 wrappedReadPlan  identifier conf sCache apiRequest@ApiRequest{iPreferences=Preferences{..},..} headersOnly = do
-  rPlan <- readPlan identifier conf sCache apiRequest
+  rPlan <- readPlan False identifier conf sCache apiRequest
   (handler, mediaType)  <- mapLeft ApiRequestError $ negotiateContent conf apiRequest identifier iAcceptMediaType (dbMediaHandlers sCache) (hasDefaultSelect rPlan)
   if not (null invalidPrefs) && preferHandling == Just Strict then Left $ ApiRequestError $ InvalidPreferences invalidPrefs else Right ()
   return $ WrappedReadPlan rPlan SQL.Read handler mediaType headersOnly identifier
 
 mutateReadPlan :: Mutation -> ApiRequest -> QualifiedIdentifier -> AppConfig -> SchemaCache -> Either Error CrudPlan
 mutateReadPlan  mutation apiRequest@ApiRequest{iPreferences=Preferences{..},..} identifier conf sCache = do
-  rPlan <- readPlan identifier conf sCache apiRequest
+  rPlan <- readPlan False identifier conf sCache apiRequest
   mPlan <- mutatePlan mutation identifier apiRequest sCache rPlan
   if not (null invalidPrefs) && preferHandling == Just Strict then Left $ ApiRequestError $ InvalidPreferences invalidPrefs else Right ()
   (handler, mediaType)  <- mapLeft ApiRequestError $ negotiateContent conf apiRequest identifier iAcceptMediaType (dbMediaHandlers sCache) (hasDefaultSelect rPlan)
@@ -173,7 +173,7 @@ callReadPlan identifier conf sCache apiRequest@ApiRequest{iPreferences=Preferenc
   proc@Function{..} <- mapLeft ApiRequestError $
     findProc identifier paramKeys (dbRoutines sCache) iContentMediaType (invMethod == Inv)
   let relIdentifier = QualifiedIdentifier pdSchema (fromMaybe pdName $ Routine.funcTableName proc) -- done so a set returning function can embed other relations
-  rPlan <- readPlan relIdentifier conf sCache apiRequest
+  rPlan <- readPlan True relIdentifier conf sCache apiRequest
   let args = case (invMethod, iContentMediaType) of
         (InvRead _, _)      -> DirectArgs $ toRpcParams proc qsParams'
         (Inv, MTUrlEncoded) -> DirectArgs $ maybe mempty (toRpcParams proc . payArray) iPayload
@@ -326,8 +326,8 @@ resolveQueryInputField ctx field opExpr = withTextParse ctx $ resolveTypeOrUnkno
 -- | Builds the ReadPlan tree on a number of stages.
 -- | Adds filters, order, limits on its respective nodes.
 -- | Adds joins conditions obtained from resource embedding.
-readPlan :: QualifiedIdentifier -> AppConfig -> SchemaCache -> ApiRequest -> Either Error ReadPlanTree
-readPlan qi@QualifiedIdentifier{..} AppConfig{configDbMaxRows, configDbAggregates} SchemaCache{dbTables, dbRelationships, dbRepresentations} apiRequest  =
+readPlan :: Bool -> QualifiedIdentifier -> AppConfig -> SchemaCache -> ApiRequest -> Either Error ReadPlanTree
+readPlan fromCallPlan qi@QualifiedIdentifier{..} AppConfig{configDbMaxRows, configDbAggregates} SchemaCache{dbTables, dbRelationships, dbRepresentations} apiRequest  =
   let
     -- JSON output format hardcoded for now. In the future we might want to support other output mappings such as CSV.
     ctx = ResolverContext dbTables dbRepresentations qi "json"
@@ -346,7 +346,8 @@ readPlan qi@QualifiedIdentifier{..} AppConfig{configDbMaxRows, configDbAggregate
     addLogicTrees ctx apiRequest =<<
     addRanges apiRequest =<<
     addOrders ctx apiRequest =<<
-    addFilters ctx apiRequest (initReadRequest ctx $ QueryParams.qsSelect $ iQueryParams apiRequest)
+    addFilters ctx apiRequest =<<
+    searchTable fromCallPlan qi dbTables (initReadRequest ctx $ QueryParams.qsSelect $ iQueryParams apiRequest)
 
 -- Build the initial read plan tree
 initReadRequest :: ResolverContext -> [Tree SelectItem] -> ReadPlanTree
@@ -744,6 +745,14 @@ validateAggFunctions aggFunctionsAllowed (Node rp@ReadPlan {select} forest)
   | not aggFunctionsAllowed && any (isJust . csAggFunction) select = Left AggregatesNotAllowed
   | otherwise = Node rp <$> traverse (validateAggFunctions aggFunctionsAllowed) forest
 
+-- We only search for the table when readPlan is not called from call plan. This
+-- is because we reuse readPlan in callReadPlan to search for function name
+searchTable :: Bool -> QualifiedIdentifier -> TablesMap -> ReadPlanTree -> Either ApiRequestError ReadPlanTree
+searchTable fromCallPlan qi@QualifiedIdentifier{..} tableMap readPlanTree =
+  case (fromCallPlan, HM.lookup qi tableMap) of
+    (False, Nothing) -> Left (TableNotFound qiSchema qiName (HM.elems tableMap))
+    _                -> Right readPlanTree
+
 addFilters :: ResolverContext -> ApiRequest -> ReadPlanTree -> Either ApiRequestError ReadPlanTree
 addFilters ctx ApiRequest{..} rReq =
   foldr addFilterToNode (Right rReq) flts
@@ -967,7 +976,7 @@ mutatePlan mutation qi ApiRequest{iPreferences=Preferences{..}, ..} SchemaCache{
     typedColumnsOrError = resolveOrError ctx tbl `traverse` S.toList iColumns
 
 resolveOrError :: ResolverContext -> Maybe Table -> FieldName -> Either ApiRequestError CoercibleField
-resolveOrError _ Nothing _ = Left NotFound
+resolveOrError ctx Nothing _ = Left $ TableNotFound (qiSchema (qi ctx)) (qiName (qi ctx)) (HM.elems (tables ctx))
 resolveOrError ctx (Just table) field =
   case resolveTableFieldName table field Nothing of
     CoercibleField{cfIRType=""} -> Left $ ColumnNotFound (tableName table) field

test/io/test_big_schema.py

@@ -7,8 +7,8 @@
 from postgrest import *
 
 
-def test_requests_wait_for_schema_cache_reload(defaultenv):
-    "requests that use the schema cache (e.g. resource embedding) wait for the schema cache to reload"
+def test_requests_with_resource_embedding_wait_for_schema_cache_reload(defaultenv):
+    "requests that use the schema cache with resource embedding wait long for the schema cache to reload"
 
     env = {
         **defaultenv,
@@ -34,6 +34,33 @@ def test_requests_wait_for_schema_cache_reload(defaultenv):
         assert plan_dur > 10000.0
 
 
+def test_requests_without_resource_embedding_wait_for_schema_cache_reload(defaultenv):
+    "requests that use the schema cache without resource embedding wait less for the schema cache to reload"
+
+    env = {
+        **defaultenv,
+        "PGRST_DB_SCHEMAS": "apflora",
+        "PGRST_DB_POOL": "2",
+        "PGRST_DB_ANON_ROLE": "postgrest_test_anonymous",
+        "PGRST_SERVER_TIMING_ENABLED": "true",
+    }
+
+    with run(env=env, wait_max_seconds=30) as postgrest:
+        # reload the schema cache
+        response = postgrest.session.get("/rpc/notify_pgrst")
+        assert response.status_code == 204
+
+        postgrest.wait_until_scache_starts_loading()
+
+        response = postgrest.session.get("/tpopmassn")
+        assert response.status_code == 200
+
+        plan_dur = parse_server_timings_header(response.headers["Server-Timing"])[
+            "plan"
+        ]
+        assert plan_dur < 10000.0
+
+
 # TODO: This test fails now because of https://github.com/PostgREST/postgrest/pull/2122
 # The stack size of 1K(-with-rtsopts=-K1K) is not enough and this fails with "stack overflow"
 # A stack size of 200K seems to be enough for succeess
@@ -65,6 +92,6 @@ def test_should_not_fail_with_stack_overflow(defaultenv):
 
     with run(env=env, wait_max_seconds=30) as postgrest:
         response = postgrest.session.get("/unknown-table?select=unknown-rel(*)")
-        assert response.status_code == 400
+        assert response.status_code == 404
         data = response.json()
-        assert data["code"] == "PGRST200"
+        assert data["code"] == "PGRST205"

test/io/test_io.py

@@ -973,11 +973,10 @@ def test_log_level(level, defaultenv):
                 r'- - postgrest_test_anonymous \[.+\] "GET /unknown HTTP/1.1" 404 - "" "python-requests/.+"',
                 output[2],
             )
+
+            assert len(output) == 5
             assert "Connection" and "is available" in output[3]
-            assert "Connection" and "is available" in output[4]
-            assert "Connection" and "is used" in output[5]
-            assert "Connection" and "is used" in output[6]
-            assert len(output) == 7
+            assert "Connection" and "is used" in output[4]
 
 
 def test_no_pool_connection_required_on_bad_http_logic(defaultenv):

test/spec/Feature/ConcurrentSpec.hs

@@ -24,12 +24,8 @@ spec =
     it "should not raise 'transaction in progress' error" $
       raceTest 10 $
         get "/fakefake"
-          `shouldRespondWith` [json|
-              { "hint": null,
-                "details":null,
-                "code":"42P01",
-                "message":"relation \"test.fakefake\" does not exist"
-              } |]
+          `shouldRespondWith`
+          [json| {"code":"PGRST205","details":null,"hint":"Perhaps you meant the relation 'test.factories'","message":"Could not find relation 'test.fakefake' in the schema cache"} |]
           { matchStatus  = 404
           , matchHeaders = []
           }

test/spec/Feature/Query/DeleteSpec.hs

@@ -109,7 +109,12 @@ spec =
 
     context "totally unknown route" $
       it "fails with 404" $
-        request methodDelete "/foozle?id=eq.101" [] "" `shouldRespondWith` 404
+        request methodDelete "/foozle?id=eq.101" [] ""
+          `shouldRespondWith`
+          [json| {"code":"PGRST205","details":null,"hint":"Perhaps you meant the relation 'test.foo'","message":"Could not find relation 'test.foozle' in the schema cache"} |]
+          { matchStatus = 404
+          , matchHeaders = []
+          }
 
     context "table with limited privileges" $ do
       it "fails deleting the row when return=representation and selecting all the columns" $

test/spec/Feature/Query/InsertSpec.hs

@@ -477,7 +477,7 @@ spec actualPgVersion = do
             {"id": 204, "body": "yyy"},
             {"id": 205, "body": "zzz"}]|]
           `shouldRespondWith`
-          [json|{} |]
+          [json| {"code":"PGRST205","details":null,"hint":"Perhaps you meant the relation 'test.articles'","message":"Could not find relation 'test.garlic' in the schema cache"} |]
           { matchStatus  = 404
           , matchHeaders = []
           }

test/spec/Feature/Query/MultipleSchemaSpec.hs

@@ -64,7 +64,13 @@ spec =
           }
 
       it "doesn't find another_table in schema v1" $
-        request methodGet "/another_table" [("Accept-Profile", "v1")] "" `shouldRespondWith` 404
+        request methodGet "/another_table"
+          [("Accept-Profile", "v1")] ""
+          `shouldRespondWith`
+          [json| {"code":"PGRST205","details":null,"hint":null,"message":"Could not find relation 'v1.another_table' in the schema cache"} |]
+          { matchStatus = 404
+          , matchHeaders = []
+          }
 
       it "fails trying to read table from unkown schema" $
         request methodGet "/parents" [("Accept-Profile", "unkown")] "" `shouldRespondWith`

test/spec/Feature/Query/QuerySpec.hs

@@ -24,7 +24,12 @@ spec = do
 
   describe "Querying a nonexistent table" $
     it "causes a 404" $
-      get "/faketable" `shouldRespondWith` 404
+      get "/faketable"
+      `shouldRespondWith`
+      [json| {"code":"PGRST205","details":null,"hint":"Perhaps you meant the relation 'test.private_table'","message":"Could not find relation 'test.faketable' in the schema cache"} |]
+      { matchStatus = 404
+      , matchHeaders = []
+      }
 
   describe "Filtering response" $ do
     it "matches with equality" $
@@ -819,14 +824,12 @@ spec = do
           , matchHeaders = [matchContentTypeJson]
           }
 
-      it "cannot request a partitioned table as parent from a partition" $
+      -- we only search for foreign key relationships after checking the
+      -- the existence of first table, #3869
+      it "table not found error if first table does not exist" $
         get "/car_model_sales_202101?select=id,name,car_models(id,name)&order=id.asc" `shouldRespondWith`
-          [json|
-            {"hint":"Perhaps you meant 'car_model_sales' instead of 'car_model_sales_202101'.",
-             "details":"Searched for a foreign key relationship between 'car_model_sales_202101' and 'car_models' in the schema 'test', but no matches were found.",
-             "code":"PGRST200",
-             "message":"Could not find a relationship between 'car_model_sales_202101' and 'car_models' in the schema cache"} |]
-          { matchStatus  = 400
+          [json| {"code":"PGRST205","details":null,"hint":"Perhaps you meant the relation 'test.car_model_sales'","message":"Could not find relation 'test.car_model_sales_202101' in the schema cache"} |]
+          { matchStatus  = 404
           , matchHeaders = [matchContentTypeJson]
           }
 
@@ -841,14 +844,10 @@ spec = do
           , matchHeaders = [matchContentTypeJson]
           }
 
-      it "cannot request partitioned tables as children from a partition" $
+      it "table not found error if first table does not exist" $
         get "/car_models_default?select=id,name,car_model_sales(id,name)&order=id.asc" `shouldRespondWith`
-          [json|
-            {"hint":"Perhaps you meant 'car_model_sales' instead of 'car_models_default'.",
-             "details":"Searched for a foreign key relationship between 'car_models_default' and 'car_model_sales' in the schema 'test', but no matches were found.",
-             "code":"PGRST200",
-             "message":"Could not find a relationship between 'car_models_default' and 'car_model_sales' in the schema cache"} |]
-          { matchStatus  = 400
+          [json| {"code":"PGRST205","details":null,"hint":"Perhaps you meant the relation 'test.car_model_sales'","message":"Could not find relation 'test.car_models_default' in the schema cache"} |]
+          { matchStatus  = 404
           , matchHeaders = [matchContentTypeJson]
           }
 

test/spec/Feature/Query/UpdateSpec.hs

@@ -17,7 +17,12 @@ spec = do
       it "indicates no table found by returning 404" $
         request methodPatch "/fake" []
           [json| { "real": false } |]
-            `shouldRespondWith` 404
+          `shouldRespondWith`
+          [json| {"code":"PGRST205","details":null,"hint":"Perhaps you meant the relation 'test.factories'","message":"Could not find relation 'test.fake' in the schema cache"} |]
+          { matchStatus = 404
+          , matchHeaders = []
+          }
+
 
     context "on an empty table" $
       it "succeeds with status code 204" $
@@ -343,7 +348,7 @@ spec = do
             {"id": 204, "body": "yyy"},
             {"id": 205, "body": "zzz"}]|]
           `shouldRespondWith`
-          [json|{} |]
+          [json| {"code":"PGRST205","details":null,"hint":"Perhaps you meant the relation 'test.articles'","message":"Could not find relation 'test.garlic' in the schema cache"} |]
           { matchStatus  = 404
           , matchHeaders = []
           }