Populate table with repartitions

Question

Hello everyone,
I would like some input on a problem to which I cannot seem to find a proper solution.
I have five tables:
Halls (_hall_, nr_places, nr_extra_places);
Students (_id_student, name, major, year );
Exams (year,major,id_subject,date_exam ,hour);
Halls_exams (hall, date_exam, hour, id_subject);
Repartition_exams (id_student, id_subject, date_exam, hour, hall);I’m trying to create a procedure or function to populate the fifth table (repartitions_exams) with students, repartitions for exams per halls and hours.
It is important to keep in mind the number of places from each hall and at the same time, a hall must have students of the same year, major and id_subject, sorted alphabetically.
I have tried solving this using a cursor but I failed in making it a viable solution.
If you could give me any hints or possible solutions to this I would highly appreciate it.
Thank you in advance,
Ella
-----edit
these are the tables and inserts that I worked on...I apologize for any mistakes. I had to translate and to remove some columns that were irrelevant to the issue.
create table halls(
hall varchar(4) constraint pk_halls_hall primary key,
nr_places numeric(4),
nr_extra_places numeric(2)
create table students(
id_student varchar(20) constraint pk_students_id_student primary key,
name varchar(30),
year numeric(4),
major varchar(20)
create table exams(
year numeric(4),
major varchar(20),
id_subject numeric(4),
date_exam date,
hour numeric(2),
constraint pk_exams primary key(year,major,id_subject,date_exam)
create table halls_exams(
hall varchar(4) constraint fk_halls_exams_hall references halls(hall),
date_exam date,
hour numeric(2),
id_subject numeric(4),
constraint pk_halls_exams primary key(hall,date_exam,hour)
create table repartition_exams(
id_student varchar(20) constraint fk_repart_exams_id_student references students(id_student),
id_subject numeric(4),
date_exam date,
hour numeric(2),
hall varchar(4) constraint fk_repart_exams_hall references halls(hall),
constraint pk_repart_exams primary key(id_student,id_subject,date_exam)
insert into halls(hall,nr_places,nr_extra_places) values ('B1',10,2);
insert into halls(hall,nr_places,nr_extra_places) values ('B3',10,2);
insert into halls(hall,nr_places,nr_extra_places) values ('B4',12,2);
insert into students(id_student,name,year,major) values ('pm095631','name1',2,'IE');
insert into students(id_student,name,year,major) values ('pm095632','name2',2,'IE');
insert into students(id_student,name,year,major) values ('pm095633','name3',2,'IE');
insert into students(id_student,name,year,major) values ('pm095634','name4',2,'IE');
insert into students(id_student,name,year,major) values ('pm095635','name5',2,'IE');
insert into students(id_student,name,year,major) values ('pm095636','name6',2,'IE');
insert into students(id_student,name,year,major) values ('pm095637','name7',2,'IE');
insert into students(id_student,name,year,major) values ('pm095638','name8',2,'IE');
insert into students(id_student,name,year,major) values ('pm095639','name9',2,'IE');
insert into students(id_student,name,year,major) values ('pm095640','name10',2,'IE');
insert into students(id_student,name,year,major) values ('pm095641','name11',2,'IE');
insert into students(id_student,name,year,major) values ('pm095642','name12',2,'IE');
insert into students(id_student,name,year,major) values ('pm095643','name13',2,'IE');
insert into students(id_student,name,year,major) values ('pm095644','name14',2,'Ai');
insert into students(id_student,name,year,major) values ('pm095645','name14',2,'Finances');
insert into students(id_student,name,year,major) values ('pm095646','name15',2,'Ai');
insert into students(id_student,name,year,major) values ('pm095647','name16',2,'Ects');
insert into students(id_student,name,year,major) values ('pm095648','name17',2,'Ects');
insert into exams(year,major,id_subject,date_exam,hour) values (2,'IE',115,TO_DATE('15/10/10','DD/MM/YY'),12);
insert into exams(year,major,id_subject,date_exam,hour) values (3,'IE',125,TO_DATE('16/10/10','DD/MM/YY'),14);
insert into exams(year,major,id_subject,date_exam,hour) values (1,'IE',135,TO_DATE('17/10/10','DD/MM/YY'),10);
insert into exams(year,major,id_subject,date_exam,hour) values (3,'IE',145,TO_DATE('18/10/10','DD/MM/YY'),18);
insert into halls_exams(hall,date_exam,hour,id_subject) values ('B1',TO_DATE('15/10/10','DD/MM/YY'),12,115);
insert into halls_exams(hall,date_exam,hour,id_subject) values ('B3',TO_DATE('15/10/10','DD/MM/YY'),12,115);
insert into halls_exams(hall,date_exam,hour,id_subject) values ('B4',TO_DATE('17/10/10','DD/MM/YY'),10,135);Edited by: user11973351 on Oct 6, 2010 5:49 AM
Edited by: user11973351 on Oct 6, 2010 1:23 PM

Answer 1

Ella,
I think I understand what you're trying to do and the following example should work, but you may have to tweak it if some of my assumptions are incorrect.
I used the row_number analytic function to assign a seat number to each student in an exam, and analytic sum functions to assign ranges of seat numbers to each hall for an exam. Then I selected students whose seat numbers were within those ranges.
I ordered the students by id but you can order by name if you prefer. I also made an assumption that you want to assign the "extra" seats only after all regular seats have been assigned.
I included the derived seat numbers and ranges in the output to make the logic easier to follow.
Regards,
Bob
-- Generating test data...
with halls as (
select 1 as hall,10 as nr_places,2 as nr_extra_places from dual union all
select 3 as hall,10 as nr_places,2 as nr_extra_places from dual union all
select 4 as hall,12 as nr_places,2 as nr_extra_places from dual
, students as (
select 'pm095631' as id_student,'name1'  as sname,2 as yr,'IE'         as major from dual union all
select 'pm095632' as id_student,'name2'  as sname,2 as yr,'IE'         as major from dual union all
select 'pm095633' as id_student,'name3'  as sname,2 as yr,'IE'         as major from dual union all
select 'pm095634' as id_student,'name4'  as sname,2 as yr,'IE'         as major from dual union all
select 'pm095635' as id_student,'name5'  as sname,2 as yr,'IE'         as major from dual union all
select 'pm095636' as id_student,'name6'  as sname,2 as yr,'IE'         as major from dual union all
select 'pm095637' as id_student,'name7'  as sname,2 as yr,'IE'         as major from dual union all
select 'pm095638' as id_student,'name8'  as sname,2 as yr,'IE'         as major from dual union all
select 'pm095639' as id_student,'name9'  as sname,2 as yr,'IE'         as major from dual union all
select 'pm095640' as id_student,'name10' as sname,2 as yr,'IE'         as major from dual union all
select 'pm095641' as id_student,'name11' as sname,2 as yr,'IE'         as major from dual union all
select 'pm095642' as id_student,'name12' as sname,2 as yr,'IE'         as major from dual union all
select 'pm095643' as id_student,'name13' as sname,2 as yr,'IE'         as major from dual union all
select 'pm095644' as id_student,'name13' as sname,2 as yr,'IE'         as major from dual union all
select 'pm095645' as id_student,'name13' as sname,2 as yr,'IE'         as major from dual union all
select 'pm095646' as id_student,'name13' as sname,2 as yr,'IE'         as major from dual union all
select 'pm095647' as id_student,'name13' as sname,2 as yr,'IE'         as major from dual union all
select 'pm095648' as id_student,'name13' as sname,2 as yr,'IE'         as major from dual union all
select 'pm095649' as id_student,'name13' as sname,2 as yr,'IE'         as major from dual union all
select 'pm095650' as id_student,'name13' as sname,2 as yr,'IE'         as major from dual union all
select 'pm095651' as id_student,'name13' as sname,2 as yr,'IE'         as major from dual union all
select 'pm095652' as id_student,'name13' as sname,2 as yr,'IE'         as major from dual union all
select 'pm095653' as id_student,'name13' as sname,2 as yr,'IE'         as major from dual union all
select 'pm095654' as id_student,'name13' as sname,2 as yr,'IE'         as major from dual union all
select 'pm095644' as id_student,'name14' as sname,2 as yr,'Ai'         as major from dual union all
select 'pm095645' as id_student,'name14' as sname,2 as yr,'Finances'   as major from dual union all
select 'pm095646' as id_student,'name15' as sname,2 as yr,'Ai'         as major from dual union all
select 'pm095647' as id_student,'name16' as sname,2 as yr,'Ects'       as major from dual union all
select 'pm095648' as id_student,'name17' as sname,2 as yr,'Ects'       as major from dual
, exams as (
select 2 as yr,'IE' as major,115 as id_subject,TO_DATE('15/10/10','DD/MM/YY') as date_exam,12 as hour_exam from dual union all
select 3 as yr,'IE' as major,125 as id_subject,TO_DATE('16/10/10','DD/MM/YY') as date_exam,14 as hour_exam from dual union all
select 1 as yr,'IE' as major,135 as id_subject,TO_DATE('17/10/10','DD/MM/YY') as date_exam,10 as hour_exam from dual union all
select 3 as yr,'IE' as major,145 as id_subject,TO_DATE('18/10/10','DD/MM/YY') as date_exam,18 as hour_exam from dual
, halls_exams as (
select 1 as hall,TO_DATE('15/10/10','DD/MM/YY') as date_exam,12 as hour_exam,115 as id_subject from dual union all
select 3 as hall,TO_DATE('15/10/10','DD/MM/YY') as date_exam,12 as hour_exam,115 as id_subject from dual union all
select 4 as hall,TO_DATE('17/10/10','DD/MM/YY') as date_exam,10 as hour_exam,135 as id_subject from dual
-- ...end of test data
select s.id_student, x.id_subject, x.date_exam, h.hour_exam, h.hall, s.rn, h.rn_min, h.rn_max,h.xrn_min, h.xrn_max
from exams x
  select date_exam, hour_exam, id_subject, hx.hall, nr_places
  , nvl(
     sum(h.nr_places) over (
       partition by date_exam, hour_exam, id_subject
       order by hx.hall
       range between unbounded preceding and 1 preceding
     ,0
     ) + 1 as rn_min
  , nvl(
     sum(h.nr_places) over (
       partition by date_exam, hour_exam, id_subject
       order by hx.hall
       range between unbounded preceding and current row
    ,0
    )     as rn_max
  , nvl(
     sum(h.nr_places) over (
       partition by date_exam, hour_exam, id_subject
       order by hx.hall
       range between unbounded preceding and unbounded following
     ,0
     +   nvl(
     sum(h.nr_extra_places) over (
       partition by date_exam, hour_exam, id_subject
       order by hx.hall
       range between unbounded preceding and 1 preceding
     ,0
     + 1 as xrn_min
  , nvl(
     sum(h.nr_places) over (
       partition by date_exam, hour_exam, id_subject
       order by hx.hall
       range between unbounded preceding and unbounded following
     ,0
     +   nvl(
     sum(h.nr_extra_places) over (
       partition by date_exam, hour_exam, id_subject
       order by hx.hall
       range between unbounded preceding and current row
     ,0
     as xrn_max
  from halls_exams hx
     , halls       h
  where h.hall = hx.hall
  ) h
, (select id_student,sname, yr, major, row_number() over(partition by yr,major order by id_student) as rn from students) s
where h.id_subject=x.id_subject
and   h.date_exam = x.date_exam
and   h.hour_exam = x.hour_exam
and   s.yr=x.yr
and   s.major=x.major
and   (s.rn between h.rn_min and h.rn_max
    or s.rn between h.xrn_min and h.xrn_max
order by s.id_student
ID_STUDENT ID_SUBJECT DATE_EXAM   HOUR_EXAM  HALL  RN  RN_MIN  RN_MAX  XRN_MIN  XRN_MAX 
pm095631   115        2010/10/15  12         1     1   1       10      21       22      
pm095632   115        2010/10/15  12         1     2   1       10      21       22      
pm095633   115        2010/10/15  12         1     3   1       10      21       22      
pm095634   115        2010/10/15  12         1     4   1       10      21       22      
pm095635   115        2010/10/15  12         1     5   1       10      21       22      
pm095636   115        2010/10/15  12         1     6   1       10      21       22      
pm095637   115        2010/10/15  12         1     7   1       10      21       22      
pm095638   115        2010/10/15  12         1     8   1       10      21       22      
pm095639   115        2010/10/15  12         1     9   1       10      21       22      
pm095640   115        2010/10/15  12         1     10  1       10      21       22      
pm095641   115        2010/10/15  12         3     11  11      20      23       24      
pm095642   115        2010/10/15  12         3     12  11      20      23       24      
pm095643   115        2010/10/15  12         3     13  11      20      23       24      
pm095644   115        2010/10/15  12         3     14  11      20      23       24      
pm095645   115        2010/10/15  12         3     15  11      20      23       24      
pm095646   115        2010/10/15  12         3     16  11      20      23       24      
pm095647   115        2010/10/15  12         3     17  11      20      23       24      
pm095648   115        2010/10/15  12         3     18  11      20      23       24      
pm095649   115        2010/10/15  12         3     19  11      20      23       24      
pm095650   115        2010/10/15  12         3     20  11      20      23       24      
pm095651   115        2010/10/15  12         1     21  1       10      21       22      
pm095652   115        2010/10/15  12         1     22  1       10      21       22      
pm095653   115        2010/10/15  12         3     23  11      20      23       24      
pm095654   115        2010/10/15  12         3     24  11      20      23       24      
24 rows selected