[null] Fix queries null aggregates

Author: jamesgpearce

src/@types/queries/index.d.ts

@@ -15,7 +15,7 @@ export type ResultTable = {[rowId: Id]: ResultRow};
 export type ResultRow = {[cellId: Id]: ResultCell};
 
 /// ResultCell
-export type ResultCell = string | number | boolean;
+export type ResultCell = string | number | boolean | null;
 
 /// ResultCellOrUndefined
 export type ResultCellOrUndefined = ResultCell | undefined;

src/queries/index.ts

@@ -365,7 +365,7 @@ export const createQueries = getCreateFunction((store: Store): Queries => {
                       );
                       groupRow[groupedCellId] = (
                         isUndefined(getCellOrValueType(aggregateValue))
-                          ? null
+                          ? undefined
                           : aggregateValue
                       ) as Cell;
                     },