i get an error when i try to run this query in the line of is nullso what is the wrongSELECT customers.comp_id, ctrl.comp_name, customers.section_code, locations.location_name AS section_name, customers.branch_code, locations_2.location_name AS branch_name, customers.group_code, locations_1.location_name AS group_name, customers.cust_address, customers.file_no, customers.cust_name, (CASE WHEN ([meter_status_code]=1 Or IsNull(([meter_status_code],1))) THEN 1 ELSE 0 END) AS mtr_1, (CASE WHEN ([meter_status_code]=2) THEN 1 ELSE 0 END) AS mtr_2, (CASE WHEN ([meter_status_code]=3) THEN 1 ELSE 0 END) AS mtr_3, (CASE WHEN ([meter_status_code]=4) THEN 1 ELSE 0 END) AS mtr_4, (CASE WHEN ([meter_status_code]=5) THEN 1 ELSE 0 END) AS mtr_5, (CASE WHEN ([meter_status_code]=9) THEN 1 ELSE 0 END) AS mtr_9, customers.stamp_date, customers.stamp_time, customers.stamp_user, users.user_descr, customers.meter_status_date, customers.activity_code, CONVERT(int,([activity_code]/100)) AS main_act, CONVERT(int,([activity_code]/10000)) AS cust_typeFROM users RIGHT JOIN (ctrl RIGHT JOIN ((locations AS locations_2 RIGHT JOIN (customers LEFT JOIN locations ON customers.section_code = locations.location_code) ON locations_2.location_code = customers.branch_code) LEFT JOIN locations AS locations_1 ON customers.group_code = locations_1.location_code) ON ctrl.comp_id = customers.comp_id) ON users.user_id = customers.stamp_user;