chore(server): allow non-nullable NQ -> NQ object relationships

PR-URL: https://github.com/hasura/graphql-engine-mono/pull/9353
GitOrigin-RevId: 9da95675d224f3045509592c2515b7afa2500d00

server/src-lib/Hasura/Backends/MSSQL/FromIr/Query.hs

@@ -204,6 +204,7 @@ fromRemoteRelationFieldsG existingJoins joinColumns (IR.FieldName name, field) =
       IR.AnnRelationSelectG
         (IR.RelName $ mkNonEmptyTextUnsafe name)
         joinColumns
+        IR.Nullable
         annotatedRelationship
 
 -- | Top/root-level 'Select'. All descendent/sub-translations are collected to produce a root TSQL.Select.

server/src-lib/Hasura/Backends/Postgres/Translate/Select/Internal/GenerateSelect.hs

@@ -31,6 +31,7 @@ import Hasura.Backends.Postgres.Translate.Select.Internal.Helpers
 import Hasura.Backends.Postgres.Translate.Types
 import Hasura.Prelude
 import Hasura.RQL.IR.Select (ConnectionSlice (SliceFirst, SliceLast))
+import Hasura.RQL.Types.Relationships.Local (Nullable (..))
 
 generateSQLSelect ::
   -- | Pre join condition for lateral joins
@@ -86,9 +87,9 @@ generateSQLSelect joinCondition selectSource selectNode =
       S.WhereFrag $ S.simplifyBoolExp $ S.BEBin S.AndOp joinCond whereCond
 
     -- function to create a joined from item from two from items
-    leftOuterJoin current new =
+    leftOuterJoin current (new, joinType) =
       S.FIJoin
-        $ S.JoinExpr current S.LeftOuter new
+        $ S.JoinExpr current joinType new
         $ S.JoinOn
         $ S.BELit True
 
@@ -102,33 +103,40 @@ generateSQLSelect joinCondition selectSource selectNode =
         <> map computedFieldToFromItem (HashMap.toList computedFields)
 
     objectRelationToFromItem ::
-      (ObjectRelationSource, SelectNode) -> S.FromItem
+      (ObjectRelationSource, SelectNode) -> (S.FromItem, S.JoinType)
     objectRelationToFromItem (objectRelationSource, node) =
-      let ObjectRelationSource _ colMapping objectSelectSource = objectRelationSource
+      let ObjectRelationSource
+            { _orsRelationMapping = colMapping,
+              _orsSelectSource = objectSelectSource,
+              _orsNullable = nullable
+            } = objectRelationSource
           alias = S.toTableAlias $ _ossPrefix objectSelectSource
           source = objectSelectSourceToSelectSource objectSelectSource
           select = generateSQLSelect (mkJoinCond baseSelectIdentifier colMapping) source node
-       in S.mkLateralFromItem select alias
+          joinType = case nullable of
+            Nullable -> S.LeftOuter
+            NotNullable -> S.Inner
+       in (S.mkLateralFromItem select alias, joinType)
 
     arrayRelationToFromItem ::
-      (ArrayRelationSource, MultiRowSelectNode) -> S.FromItem
+      (ArrayRelationSource, MultiRowSelectNode) -> (S.FromItem, S.JoinType)
     arrayRelationToFromItem (arrayRelationSource, arraySelectNode) =
       let ArrayRelationSource _ colMapping source = arrayRelationSource
           alias = S.toTableAlias $ _ssPrefix source
           select =
             generateSQLSelectFromArrayNode source arraySelectNode
               $ mkJoinCond baseSelectIdentifier colMapping
-       in S.mkLateralFromItem select alias
+       in (S.mkLateralFromItem select alias, S.LeftOuter)
 
     arrayConnectionToFromItem ::
-      (ArrayConnectionSource, MultiRowSelectNode) -> S.FromItem
+      (ArrayConnectionSource, MultiRowSelectNode) -> (S.FromItem, S.JoinType)
     arrayConnectionToFromItem (arrayConnectionSource, arraySelectNode) =
       let selectWith = connectionToSelectWith baseSelectAlias arrayConnectionSource arraySelectNode
           alias = S.toTableAlias $ _ssPrefix $ _acsSource arrayConnectionSource
-       in S.FISelectWith (S.Lateral True) selectWith alias
+       in (S.FISelectWith (S.Lateral True) selectWith alias, S.LeftOuter)
 
     computedFieldToFromItem ::
-      (ComputedFieldTableSetSource, MultiRowSelectNode) -> S.FromItem
+      (ComputedFieldTableSetSource, MultiRowSelectNode) -> (S.FromItem, S.JoinType)
     computedFieldToFromItem (computedFieldTableSource, node) =
       let ComputedFieldTableSetSource _ source = computedFieldTableSource
           internalSelect = generateSQLSelect (S.BELit True) source $ _mrsnSelectNode node
@@ -138,7 +146,7 @@ generateSQLSelect joinCondition selectSource selectNode =
               { S.selExtr = _mrsnTopExtractors node,
                 S.selFrom = Just $ S.FromExp [S.mkSelFromItem internalSelect alias]
               }
-       in S.mkLateralFromItem select alias
+       in (S.mkLateralFromItem select alias, S.LeftOuter)
 
 -- | Create a select query
 generateSQLSelectFromArrayNode ::

server/src-lib/Hasura/Backends/Postgres/Translate/Select/Internal/OrderBy.hs

@@ -130,7 +130,7 @@ processOrderByItems sourcePrefix' fieldAlias' similarArrayFields distOnCols = \c
                       (tableIdentifierToIdentifier relSourcePrefix)
                       (S.FISimple relTable Nothing)
                       (toSQLBoolExp (S.QualTable relTable) relFilter)
-                  relSource = ObjectRelationSource relName colMapping selectSource
+                  relSource = ObjectRelationSource relName colMapping selectSource Nullable
               pure
                 ( relSource,
                   HashMap.singleton relOrderByAlias relOrdByExp,

server/src-lib/Hasura/Backends/Postgres/Translate/Select/Internal/Process.hs

@@ -291,7 +291,7 @@ processAnnFields sourcePrefix fieldAlias similarArrFields annFields tCase = do
         AFNodeId _ sn tn pKeys -> pure $ mkNodeId sn tn pKeys
         AFColumn c -> toSQLCol c
         AFObjectRelation objSel -> withWriteObjectRelation $ do
-          let AnnRelationSelectG relName relMapping annObjSel = objSel
+          let AnnRelationSelectG relName relMapping nullable annObjSel = objSel
               AnnObjectSelectG objAnnFields target targetFilter = annObjSel
               objRelSourcePrefix = mkObjectRelationTableAlias sourcePrefix relName
               sourcePrefixes = mkSourcePrefixes objRelSourcePrefix
@@ -314,7 +314,7 @@ processAnnFields sourcePrefix fieldAlias similarArrFields annFields tCase = do
                       (_pfThis sourcePrefixes)
                       (S.FIIdentifier nativeQueryIdentifier)
                       (toSQLBoolExp (S.QualifiedIdentifier nativeQueryIdentifier Nothing) targetFilter)
-                  objRelSource = ObjectRelationSource relName relMapping selectSource
+                  objRelSource = ObjectRelationSource relName relMapping selectSource nullable
               pure
                 ( objRelSource,
                   HashMap.fromList [annFieldsExtr],
@@ -326,7 +326,7 @@ processAnnFields sourcePrefix fieldAlias similarArrFields annFields tCase = do
                       (_pfThis sourcePrefixes)
                       (S.FISimple tableFrom Nothing)
                       (toSQLBoolExp (S.QualTable tableFrom) targetFilter)
-                  objRelSource = ObjectRelationSource relName relMapping selectSource
+                  objRelSource = ObjectRelationSource relName relMapping selectSource Nullable
               pure
                 ( objRelSource,
                   HashMap.fromList [annFieldsExtr],
@@ -496,7 +496,7 @@ processArrayRelation ::
 processArrayRelation sourcePrefixes fieldAlias relAlias arrSel _tCase =
   case arrSel of
     ASSimple annArrRel -> withWriteArrayRelation $ do
-      let AnnRelationSelectG _ colMapping sel = annArrRel
+      let AnnRelationSelectG _ colMapping _ sel = annArrRel
           permLimitSubQuery =
             maybe PLSQNotRequired PLSQRequired $ _tpLimit $ _asnPerm sel
       (source, nodeExtractors) <-
@@ -514,7 +514,7 @@ processArrayRelation sourcePrefixes fieldAlias relAlias arrSel _tCase =
           ()
         )
     ASAggregate aggSel -> withWriteArrayRelation $ do
-      let AnnRelationSelectG _ colMapping sel = aggSel
+      let AnnRelationSelectG _ colMapping _ sel = aggSel
       (source, nodeExtractors, topExtr) <-
         processAnnAggregateSelect sourcePrefixes fieldAlias sel
       pure
@@ -524,7 +524,7 @@ processArrayRelation sourcePrefixes fieldAlias relAlias arrSel _tCase =
           ()
         )
     ASConnection connSel -> withWriteArrayConnection $ do
-      let AnnRelationSelectG _ colMapping sel = connSel
+      let AnnRelationSelectG _ colMapping _ sel = connSel
       (source, topExtractor, nodeExtractors) <-
         processConnectionSelect sourcePrefixes fieldAlias relAlias colMapping sel
       pure

server/src-lib/Hasura/Backends/Postgres/Translate/Types.hs

@@ -12,7 +12,7 @@ module Hasura.Backends.Postgres.Translate.Types
     DistinctAndOrderByExpr (ASorting),
     JoinTree (..),
     MultiRowSelectNode (..),
-    ObjectRelationSource (ObjectRelationSource),
+    ObjectRelationSource (..),
     ObjectSelectSource (ObjectSelectSource, _ossPrefix),
     PermissionLimitSubQuery (..),
     SelectNode (SelectNode),
@@ -38,6 +38,7 @@ import Hasura.NativeQuery.Metadata (InterpolatedQuery)
 import Hasura.Prelude
 import Hasura.RQL.IR.Select
 import Hasura.RQL.Types.Common
+import Hasura.RQL.Types.Relationships.Local (Nullable)
 
 data SourcePrefixes = SourcePrefixes
   { -- | Current source prefix
@@ -169,7 +170,8 @@ objectSelectSourceToSelectSource ObjectSelectSource {..} =
 data ObjectRelationSource = ObjectRelationSource
   { _orsRelationshipName :: RelName,
     _orsRelationMapping :: HashMap.HashMap Postgres.PGCol Postgres.PGCol,
-    _orsSelectSource :: ObjectSelectSource
+    _orsSelectSource :: ObjectSelectSource,
+    _orsNullable :: Nullable
   }
   deriving (Generic, Show)
 

server/src-lib/Hasura/GraphQL/Execute/Backend.hs

@@ -33,6 +33,7 @@ import Hasura.RQL.Types.Backend
 import Hasura.RQL.Types.BackendType
 import Hasura.RQL.Types.Column (ColumnType, fromCol)
 import Hasura.RQL.Types.Common
+import Hasura.RQL.Types.Relationships.Local (Nullable (..))
 import Hasura.RQL.Types.ResultCustomization
 import Hasura.RQL.Types.Schema.Options qualified as Options
 import Hasura.RemoteSchema.SchemaCache
@@ -197,11 +198,11 @@ convertRemoteSourceRelationship
 
       relationshipField = case relationship of
         SourceRelationshipObject s ->
-          AFObjectRelation $ AnnRelationSelectG relName columnMapping s
+          AFObjectRelation $ AnnRelationSelectG relName columnMapping Nullable s
         SourceRelationshipArray s ->
-          AFArrayRelation $ ASSimple $ AnnRelationSelectG relName columnMapping s
+          AFArrayRelation $ ASSimple $ AnnRelationSelectG relName columnMapping Nullable s
         SourceRelationshipArrayAggregate s ->
-          AFArrayRelation $ ASAggregate $ AnnRelationSelectG relName columnMapping s
+          AFArrayRelation $ ASAggregate $ AnnRelationSelectG relName columnMapping Nullable s
 
       argumentIdField =
         ( fromCol @b argumentIdColumn,

server/src-lib/Hasura/GraphQL/Schema/Select.hs

@@ -1448,7 +1448,7 @@ relationshipField table ri = runMaybeT do
         $ P.subselection_ relFieldName desc selectionSetParser
         <&> \fields ->
           IR.AFObjectRelation
-            $ IR.AnnRelationSelectG (riName ri) (riMapping ri)
+            $ IR.AnnRelationSelectG (riName ri) (riMapping ri) Nullable
             $ IR.AnnObjectSelectG fields (IR.FromTable otherTableName)
             $ deduplicatePermissions
             $ IR._tpFilter
@@ -1460,7 +1460,7 @@ relationshipField table ri = runMaybeT do
             otherTableParser <&> \selectExp ->
               IR.AFArrayRelation
                 $ IR.ASSimple
-                $ IR.AnnRelationSelectG (riName ri) (riMapping ri)
+                $ IR.AnnRelationSelectG (riName ri) (riMapping ri) Nullable
                 $ deduplicatePermissions' selectExp
           relAggFieldName = applyFieldNameCaseCust tCase $ relFieldName <> Name.__aggregate
           relAggDesc = Just $ G.Description "An aggregate relationship"
@@ -1479,8 +1479,8 @@ relationshipField table ri = runMaybeT do
       pure
         $ catMaybes
           [ Just arrayRelField,
-            fmap (IR.AFArrayRelation . IR.ASAggregate . IR.AnnRelationSelectG (riName ri) (riMapping ri)) <$> remoteAggField,
+            fmap (IR.AFArrayRelation . IR.ASAggregate . IR.AnnRelationSelectG (riName ri) (riMapping ri) Nullable) <$> remoteAggField,
-            fmap (IR.AFArrayRelation . IR.ASConnection . IR.AnnRelationSelectG (riName ri) (riMapping ri)) <$> remoteConnectionField
+            fmap (IR.AFArrayRelation . IR.ASConnection . IR.AnnRelationSelectG (riName ri) (riMapping ri) Nullable) <$> remoteConnectionField
           ]
 
 tablePermissionsInfo :: (Backend b) => SelPermInfo b -> TablePerms b

server/src-lib/Hasura/LogicalModel/Schema.hs

@@ -200,11 +200,11 @@ parseLogicalModelField relationshipInfo column logimoField = do
     ( LogicalModelField
         { lmfType =
             LogicalModelTypeReference
-              (LogicalModelTypeReferenceC {lmtrReference})
+              (LogicalModelTypeReferenceC {lmtrNullable, lmtrReference})
         }
       ) -> do
-        -- we currently ignore nullability and assume the field is nullable
         relName <- hoistMaybe $ columnToRelName @b column
+
         -- lookup the reference in the data source
         relationship <-
           InsOrdHashMap.lookup relName relationshipInfo
@@ -215,14 +215,14 @@ parseLogicalModelField relationshipInfo column logimoField = do
                   <> commaSeparated (map relNameToTxt (InsOrdHashMap.keys relationshipInfo))
                   <> "]."
               )
-        logicalModelObjectRelationshipField @b @r @m @n lmtrReference relationship
+        logicalModelObjectRelationshipField @b @r @m @n lmtrReference (nullableFromBool lmtrNullable) relationship
     ( LogicalModelField
         { lmfType =
             LogicalModelTypeArray
               ( LogicalModelTypeArrayC
                   { lmtaArray =
-                      LogicalModelTypeReference (LogicalModelTypeReferenceC {lmtrReference}),
+                      LogicalModelTypeReference (LogicalModelTypeReferenceC {lmtrReference, lmtrNullable = innerNullability}),
-                    lmtaNullable
+                    lmtaNullable = arrayNullability
                   }
                 )
         }
@@ -232,9 +232,12 @@ parseLogicalModelField relationshipInfo column logimoField = do
         relName <- hoistMaybe $ columnToRelName @b column
         -- lookup the reference in the data source
         relationship <- hoistMaybe $ InsOrdHashMap.lookup relName relationshipInfo
-        let nullability = if lmtaNullable then Nullable else NotNullable
 
-        logicalModelArrayRelationshipField @b @r @m @n lmtrReference nullability relationship
+        logicalModelArrayRelationshipField @b @r @m @n
+          lmtrReference
+          (nullableFromBool arrayNullability)
+          (nullableFromBool innerNullability)
+          relationship
     ( LogicalModelField
         { lmfType =
             LogicalModelTypeArray
@@ -250,6 +253,10 @@ parseLogicalModelField relationshipInfo column logimoField = do
       ) ->
         throw500 "Nested arrays are not currently implemented"
 
+nullableFromBool :: Bool -> Nullable
+nullableFromBool True = Nullable
+nullableFromBool False = NotNullable
+
 defaultLogicalModelSelectionSet ::
   forall b r m n.
   ( MonadBuildSchema b r m n,
@@ -421,9 +428,10 @@ logicalModelObjectRelationshipField ::
     MonadBuildSchema b r m n
   ) =>
   LogicalModelName ->
+  Nullable ->
   RelInfo b ->
   MaybeT (SchemaT r m) (FieldParser n (AnnotatedField b))
-logicalModelObjectRelationshipField logicalModelName ri | riType ri == ObjRel =
+logicalModelObjectRelationshipField logicalModelName nullability ri | riType ri == ObjRel =
   case riTarget ri of
     RelTargetNativeQuery nativeQueryName -> do
       nativeQueryInfo <- lift $ askNativeQueryInfo nativeQueryName
@@ -443,16 +451,22 @@ logicalModelObjectRelationshipField logicalModelName ri | riType ri == ObjRel =
       relFieldName <- lift $ textToName $ relNameToTxt $ riName ri
 
       let objectRelDesc = Just $ G.Description "An object relationship"
-
       nativeQueryParser <- MaybeT $ selectNativeQueryObject nativeQueryInfo relFieldName objectRelDesc
 
+      -- this only affects the generated GraphQL type
+      let nullabilityModifier =
+            case nullability of
+              Nullable -> id
+              NotNullable -> IP.nonNullableField
+
       pure
+        $ nullabilityModifier
         $ nativeQueryParser
         <&> \selectExp ->
-          IR.AFObjectRelation (IR.AnnRelationSelectG (riName ri) (riMapping ri) selectExp)
+          IR.AFObjectRelation (IR.AnnRelationSelectG (riName ri) (riMapping ri) nullability selectExp)
     RelTargetTable _otherTableName -> do
       throw500 "Object relationships from logical models to tables are not implemented"
-logicalModelObjectRelationshipField _ _ =
+logicalModelObjectRelationshipField _ _ _ =
   hoistMaybe Nothing -- the target logical model expected an object relationship, but this was an array
 
 -- | Field parsers for a logical model relationship
@@ -463,9 +477,10 @@ logicalModelArrayRelationshipField ::
   ) =>
   LogicalModelName ->
   Nullable ->
+  Nullable ->
   RelInfo b ->
   MaybeT (SchemaT r m) (FieldParser n (AnnotatedField b))
-logicalModelArrayRelationshipField logicalModelName nullability ri | riType ri == ArrRel =
+logicalModelArrayRelationshipField logicalModelName arrayNullability innerNullability ri | riType ri == ArrRel =
   case riTarget ri of
     RelTargetNativeQuery nativeQueryName -> do
       nativeQueryInfo <- lift $ askNativeQueryInfo nativeQueryName
@@ -485,15 +500,15 @@ logicalModelArrayRelationshipField logicalModelName nullability ri | riType ri =
 
       let objectRelDesc = Just $ G.Description "An array relationship"
 
-      nativeQueryParser <- MaybeT $ selectNativeQuery nativeQueryInfo relFieldName nullability objectRelDesc
+      nativeQueryParser <- MaybeT $ selectNativeQuery nativeQueryInfo relFieldName arrayNullability objectRelDesc
 
       pure
         $ nativeQueryParser
         <&> \selectExp ->
           IR.AFArrayRelation
             $ IR.ASSimple
-            $ IR.AnnRelationSelectG (riName ri) (riMapping ri) selectExp
+            $ IR.AnnRelationSelectG (riName ri) (riMapping ri) innerNullability selectExp
     RelTargetTable _otherTableName -> do
       throw500 "Array relationships from logical models to tables are not implemented"
-logicalModelArrayRelationshipField _ _ _ =
+logicalModelArrayRelationshipField _ _ _ _ =
   hoistMaybe Nothing -- the target logical model expected an array relationship, but this was an object

server/src-lib/Hasura/RQL/DML/Select.hs

@@ -292,7 +292,7 @@ convExtRel sqlGen fieldInfoMap relName mAlias selQ sessVarBldr prepValBldr = do
       when misused $ throw400 UnexpectedPayload objRelMisuseMsg
       pure
         $ Left
-        $ AnnRelationSelectG (fromMaybe relName mAlias) colMapping
+        $ AnnRelationSelectG (fromMaybe relName mAlias) colMapping Nullable
         $ AnnObjectSelectG (_asnFields annSel) (FromTable relTableName)
         $ _tpFilter
         $ _asnPerm annSel
@@ -303,6 +303,7 @@ convExtRel sqlGen fieldInfoMap relName mAlias selQ sessVarBldr prepValBldr = do
         $ AnnRelationSelectG
           (fromMaybe relName mAlias)
           colMapping
+          Nullable
           annSel
   where
     pgWhenRelErr = "only relationships can be expanded"

server/src-lib/Hasura/RQL/IR/Select/Lenses.hs

@@ -18,6 +18,7 @@ module Hasura.RQL.IR.Select.Lenses
     aarAnnSelect,
     aarColumnMapping,
     aarRelationshipName,
+    aarNullable,
     anosSupportsNestedObjects,
     anosColumn,
     anosFields,

server/src-lib/Hasura/RQL/IR/Select/RelationSelect.hs

@@ -12,12 +12,14 @@ import Hasura.Prelude
 import Hasura.RQL.Types.Backend
 import Hasura.RQL.Types.BackendType
 import Hasura.RQL.Types.Common
+import Hasura.RQL.Types.Relationships.Local (Nullable)
 
 -- Local relationship
 
 data AnnRelationSelectG (b :: BackendType) a = AnnRelationSelectG
   { _aarRelationshipName :: RelName, -- Relationship name
     _aarColumnMapping :: HashMap (Column b) (Column b), -- Column of left table to join with
+    _aarNullable :: Nullable, -- is the target object allowed to be missing?
     _aarAnnSelect :: a -- Current table. Almost ~ to SQL Select
   }
   deriving stock (Functor, Foldable, Traversable)