Check external table types

packages/server/src/utilities/rowProcessor/index.ts

@@ -11,6 +11,7 @@ import {
   processInputBBReferences,
   processOutputBBReferences,
 } from "./bbReferenceProcessor"
+import { isExternalTable } from "../../integrations/utils"
 export * from "./utils"
 
 type AutoColumnProcessingOpts = {
@@ -251,7 +252,7 @@ export async function outputProcessing<T extends Row[] | Row>(
     )) as Row[]
   }
   // remove null properties to match internal API
-  if (table.sourceId) {
+  if (isExternalTable(table._id!)) {
     for (let row of enriched) {
       for (let key of Object.keys(row)) {
         if (row[key] === null) {