GetOleDbReader:Data Execute ErrorObject reference not set to an instance of an object.: SELECT * FROM MountingTypes LEFT JOIN (SELECT SubTypeOf AS ChildID, COUNT(MountingID) AS BranchCount FROM MountingTypes GROUP BY SubTypeOf) AS t2 ON t2.ChildID=MountingTypes.MountingID WHERE SubTypeOf= '' OR SubTypeOf IS NULL ORDER BY SortOrder ASC;
GetOleDbReader: Data Execute Error:Object reference not set to an instance of an object.