Don't modify internal API

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

@@ -251,6 +251,7 @@ export async function outputProcessing<T extends Row[] | Row>(
     )) as Row[]
   }
   // remove null properties to match internal API
+  if (table.sourceId) {
     for (let row of enriched) {
       for (let key of Object.keys(row)) {
         if (row[key] === null) {
@@ -258,6 +259,7 @@ export async function outputProcessing<T extends Row[] | Row>(
         }
       }
     }
+  }
   return (wasArray ? enriched : enriched[0]) as T
 }