diff --git a/src/Core/Services/GraphQLSchemaCreator.cs b/src/Core/Services/GraphQLSchemaCreator.cs
index d449c396c0..7c9b505e96 100644
--- a/src/Core/Services/GraphQLSchemaCreator.cs
+++ b/src/Core/Services/GraphQLSchemaCreator.cs
@@ -318,7 +318,8 @@ private DocumentNode GenerateSqlGraphQLObjects(RuntimeEntities entities, Diction
                             configEntity: entity,
                             entities: entities,
                             rolesAllowedForEntity: rolesAllowedForEntity,
-                            rolesAllowedForFields: rolesAllowedForFields);
+                            rolesAllowedForFields: rolesAllowedForFields,
+                            databaseType: sqlMetadataProvider.GetDatabaseType());
 
                         if (databaseObject.SourceType is not EntitySourceType.StoredProcedure)
                         {
@@ -560,7 +561,8 @@ private Dictionary<string, ObjectTypeDefinitionNode> GenerateObjectDefinitionsFo
                                 configEntity: linkingEntity,
                                 entities: new(new Dictionary<string, Entity>()),
                                 rolesAllowedForEntity: new List<string>(),
-                                rolesAllowedForFields: new Dictionary<string, IEnumerable<string>>()
+                                rolesAllowedForFields: new Dictionary<string, IEnumerable<string>>(),
+                                databaseType: sqlMetadataProvider.GetDatabaseType()
                             );
 
                         linkingObjectTypes.Add(linkingEntityName, node);
diff --git a/src/Service.GraphQLBuilder/Sql/SchemaConverter.cs b/src/Service.GraphQLBuilder/Sql/SchemaConverter.cs
index 257b1c1eb6..b10682e8c4 100644
--- a/src/Service.GraphQLBuilder/Sql/SchemaConverter.cs
+++ b/src/Service.GraphQLBuilder/Sql/SchemaConverter.cs
@@ -48,7 +48,8 @@ public static ObjectTypeDefinitionNode GenerateObjectTypeDefinitionForDatabaseOb
             Entity configEntity,
             RuntimeEntities entities,
             IEnumerable<string> rolesAllowedForEntity,
-            IDictionary<string, IEnumerable<string>> rolesAllowedForFields)
+            IDictionary<string, IEnumerable<string>> rolesAllowedForFields,
+            DatabaseType databaseType = DatabaseType.MSSQL)
         {
             ObjectTypeDefinitionNode objectDefinitionNode;
             switch (databaseObject.SourceType)
@@ -69,7 +70,8 @@ public static ObjectTypeDefinitionNode GenerateObjectTypeDefinitionForDatabaseOb
                         configEntity: configEntity,
                         entities: entities,
                         rolesAllowedForEntity: rolesAllowedForEntity,
-                        rolesAllowedForFields: rolesAllowedForFields);
+                        rolesAllowedForFields: rolesAllowedForFields,
+                        databaseType: databaseType);
                     break;
                 default:
                     throw new DataApiBuilderException(
@@ -170,7 +172,8 @@ private static ObjectTypeDefinitionNode CreateObjectTypeDefinitionForTableOrView
             Entity configEntity,
             RuntimeEntities entities,
             IEnumerable<string> rolesAllowedForEntity,
-            IDictionary<string, IEnumerable<string>> rolesAllowedForFields)
+            IDictionary<string, IEnumerable<string>> rolesAllowedForFields,
+            DatabaseType databaseType = DatabaseType.MSSQL)
         {
             Dictionary<string, FieldDefinitionNode> fieldDefinitionNodes = new();
             SourceDefinition sourceDefinition = databaseObject.SourceDefinition;
@@ -225,7 +228,8 @@ private static ObjectTypeDefinitionNode CreateObjectTypeDefinitionForTableOrView
                             databaseObject,
                             entities,
                             relationshipName,
-                            relationship);
+                            relationship,
+                            databaseType);
                         fieldDefinitionNodes.Add(relationshipField.Name.Value, relationshipField);
                     }
                 }
@@ -474,13 +478,14 @@ private static FieldDefinitionNode GenerateFieldForRelationship(
             DatabaseObject databaseObject,
             RuntimeEntities entities,
             string relationshipName,
-            EntityRelationship relationship)
+            EntityRelationship relationship,
+            DatabaseType databaseType = DatabaseType.MSSQL)
         {
             // Generate the field that represents the relationship to ObjectType, so you can navigate through it
             // and walk the graph.
             string targetEntityName = relationship.TargetEntity.Split('.').Last();
             Entity referencedEntity = entities[targetEntityName];
-            bool isNullableRelationship = FindNullabilityOfRelationship(entityName, databaseObject, targetEntityName);
+            bool isNullableRelationship = FindNullabilityOfRelationship(entityName, databaseObject, targetEntityName, databaseType);
 
             INullableTypeNode targetField = relationship.Cardinality switch
             {
@@ -631,8 +636,15 @@ public static IValueNode CreateValueNodeFromDbObjectMetadata(object metadataValu
         private static bool FindNullabilityOfRelationship(
             string entityName,
             DatabaseObject databaseObject,
-            string targetEntityName)
+            string targetEntityName,
+            DatabaseType databaseType = DatabaseType.MSSQL)
         {
+            // DWSQL does not enforce foreign key constraints, so relationship fields are always nullable.
+            if (databaseType == DatabaseType.DWSQL)
+            {
+                return true;
+            }
+
             bool isNullableRelationship = false;
             SourceDefinition sourceDefinition = databaseObject.SourceDefinition;
             if (// Retrieve all the relationship information for the source entity which is backed by this table definition
diff --git a/src/Service.Tests/GraphQLBuilder/Sql/SchemaConverterTests.cs b/src/Service.Tests/GraphQLBuilder/Sql/SchemaConverterTests.cs
index 164c9d6f05..76d0701e57 100644
--- a/src/Service.Tests/GraphQLBuilder/Sql/SchemaConverterTests.cs
+++ b/src/Service.Tests/GraphQLBuilder/Sql/SchemaConverterTests.cs
@@ -361,6 +361,21 @@ public void ForeignKeyFieldHasCorrectNullability(bool isNullable)
             Assert.AreEqual(expected: isNullable, actual: field.Type is INullableTypeNode);
         }
 
+        // A NOT NULL foreign-key column yields a non-nullable relationship field for MSSQL, but a
+        // nullable one for DWSQL since DWSQL does not enforce foreign key constraints.
+        [DataRow(DatabaseType.DWSQL, Cardinality.One, true, DisplayName = "Many-to-one relationship field is nullable for DWSQL despite NOT NULL FK.")]
+        [DataRow(DatabaseType.DWSQL, Cardinality.Many, true, DisplayName = "Cardinality.Many relationship field is nullable for DWSQL despite NOT NULL FK metadata.")]
+        [DataRow(DatabaseType.MSSQL, Cardinality.One, false, DisplayName = "Many-to-one relationship field is non-nullable for MSSQL with NOT NULL FK.")]
+        [DataRow(DatabaseType.MSSQL, Cardinality.Many, false, DisplayName = "Cardinality.Many relationship field is non-nullable for MSSQL with NOT NULL FK metadata.")]
+        [TestMethod]
+        public void RelationshipFieldIsNullableForDwSqlDespiteNonNullableForeignKey(DatabaseType databaseType, Cardinality cardinality, bool expectedNullable)
+        {
+            ObjectTypeDefinitionNode od =
+                GenerateObjectWithRelationship(cardinality, isNullableRelationship: false, databaseType: databaseType);
+            FieldDefinitionNode field = od.Fields.First(f => f.Name.Value == FIELD_NAME_FOR_TARGET);
+            Assert.AreEqual(expectedNullable, field.Type is INullableTypeNode);
+        }
+
         [TestMethod]
         public void WhenForeignKeyDefinedButNoRelationship_GraphQLWontModelIt()
         {
@@ -756,7 +771,7 @@ public static Entity GenerateEmptyEntity(string entityName)
             );
         }
 
-        private static ObjectTypeDefinitionNode GenerateObjectWithRelationship(Cardinality cardinality, bool isNullableRelationship = false)
+        private static ObjectTypeDefinitionNode GenerateObjectWithRelationship(Cardinality cardinality, bool isNullableRelationship = false, DatabaseType databaseType = DatabaseType.MSSQL)
         {
             SourceDefinition table = GenerateTableWithForeignKeyDefinition(isNullableRelationship);
 
@@ -786,7 +801,8 @@ private static ObjectTypeDefinitionNode GenerateObjectWithRelationship(Cardinali
                 dbObject,
                 configEntity, new(new Dictionary<string, Entity>() { { TARGET_ENTITY, relationshipEntity } }),
                 rolesAllowedForEntity: GetRolesAllowedForEntity(),
-                rolesAllowedForFields: GetFieldToRolesMap()
+                rolesAllowedForFields: GetFieldToRolesMap(),
+                databaseType: databaseType
                 );
         }