how do you enforce business rules on a database
create trigger branch_manager_trg before insert or update on branch_manager for each row declare dummy employee.employee_id%type; begin select e.employee_id into dummy from employee e where e.employee_id = :new.manager_id and e.branch_id = :new.branch_id and e.emp_type = 'MANAGER'; exception when no_data_found then raise_application_error(-20000, 'Branch manager must be a MANAGER'); end; /