Different results whether insert run alone or in begin...end

Question

I have an insert statement below. If I put in .sql file and run with @ in plsql i get 1300 rows evenly distributed to different "unique_id"(first column). If I take this exact same statement and enclose in DECLARE, BEGIN, EXCEPTION, END block with no other code changes, I get 1300 rows but they all have the same "unique_id" of 36. I'm confused. Oracle 8i on windows 2000 and SQLPlus from my desk with XP.
  insert
    into x_group_list (x_group_list.unique_id,
                      x_group_list.supervisor_sys_id,
                      x_group_list.employee_sys_id,
                      x_group_list.pay_policy_sys_id,
                      x_group_list.punch_based_entry,
                      x_group_list.cost_date_format,
                      x_group_list.pay_period_sys_id,
                      x_group_list.pay_period_short_name,
                      x_group_list.pay_period_start_date,
                      x_group_list.pay_period_end_date,
                      x_group_list.pay_period_status,
                      x_group_list.serial_number,
                      x_group_list.last_name,
                      x_group_list.first_name,
                      x_group_list.middle_name,
                      x_group_list.department_id,
                      x_group_list.department_sys_id,
                      x_group_list.workgroup_id,
                      x_group_list.location_sys_id,
                      x_group_list.location_offset,
                      x_group_list.validate_until_current_time,
                      x_group_list.approval_sys_id,
                      x_group_list.timecard_error_flag,
                      x_group_list.lock_timecard,
                      x_group_list.emp_pay_period_exists,
                      x_group_list.grp_schedule_include,
                      x_group_list.grp_gte_include,
                      x_group_list.being_used_by,
                      x_group_list.date_modified)
    select NVL(superrank, 99999),
           mysuper,
           employee.employee_sys_id,
           employee.pay_policy_sys_id,
           pay_policy.punch_based_entry,
           0,
           mypolicy,
           'SHORTNAME',
           (mydetailend - 10080),
           mydetailend,
           'H',
           employee.serial_number,
           employee.last_name,
           employee.first_name,
           employee.middle_name,
           mydep_id,
           mydep,
           'Junk',
           employee.location_sys_id,
           0,
           pay_policy.validate_until_current_time,
           0,
           1,
           0,
           'Y',
           0,
           0,
           mysuper,
           sysdate
      from employee, pay_policy,
           (select policy_pay_period_detail.system_id mypolicy,
                   min(policy_pay_period_detail.pay_period_end_date) mydetailend
              from policy_pay_period_detail
             where policy_pay_period_detail.pay_period_closed = 0
             group by policy_pay_period_detail.system_id),
           (select mydep, mydep_id, mysuper, superrank
              from (select rownum deprank, department_sys_id mydep, department_id mydep_id
                      from department
                     where department_sys_id in
                           (select distinct department_sys_id mydep
                              from employee
                             where employee_status = 'A')),
                   (select rownum superrank, employee_sys_id mysuper
                      from employee
                     where employee_status = 'A'
                       and approve_all_departments = 'Y'
                       and employee_sys_id > 1)
             where mod(deprank, 36)+1 = superrank)
    where employee.employee_status = 'A'
      and mydep = employee.department_sys_id
      and employee.pay_policy_sys_id = pay_policy.pay_policy_sys_id
      and pay_policy.pay_period_sys_id = mypolicy;thanks,
Herb
Message was edited by:
HerbLane

Answer 1

What I'm reading (since I haven't used SEQUENCE before) says that I can't use it in a subquery. fyi: Oracle 8i The Complete Reference.
My biggest concern is figuring out why it is running differently whether inside BEGIN..END or not. I just want to be sure that I'm not using something incorrectly (or the possibility of a defect which is less likely). We have too many scripts here that could give incorrect results because they are written in a simmilar fashion.