Creating frequency interval in Crystal Report - oracle

Question

I am trying to create a dataset of frequency interval in crystal report something like below. First column is rowid, second is start interval , third column is end interval and fourth column is interval name.
1 0 29 0 - 29
2 30 59 30 - 59
3 60 89 60 - 89
4 90 119 90 - 119
5 120 149 120 - 149
6 150 179 150 - 179
7 180 209 180 - 209
8 210 239 210 - 239
9 240 269 240 - 269
10 270 299 270 - 299
11 300 329 300 - 329
12 330 359 330 - 359
13 360 389 360 - 389
14 390 419 390 - 419
15 420 449 420 - 449
16 450 479 450 - 479
17 480 509 480 - 509
18 510 539 510 - 539
19 540 569 540 - 569
20 570 599 570 - 599
21 600 629 600 - 629
22 630 659 630 - 659
23 660 689 660 - 689
24 690 719 690 - 719
25 720 749 720 - 749
26 750 779 750 - 779
27 780 809 780 - 809
28 810 839 810 - 839
29 840 869 840 - 869
30 870 899 870 - 899
Can I write a CTE to generate this interval so that I can use it directly in crystal report without writing function on database side? Below is the code which I wrote:
declare intervalStart integer := 0;
intervalEnd integer := 900;
intervalMins varchar(10) := 30;
totalIntervals number := 0;
begin
begin
execute immediate 'create global temporary table intervalTable (row_Id int not null, intStart integer, intEnd integer, intervalName varchar2(25))ON COMMIT DELETE ROWS';
exception when others then dbms_output.put_line(sqlerrm);
end;
totalIntervals := intervalEnd/intervalMins;
--dbms_output.put_line(totalIntervals);
for i in 1 ..totalIntervals loop
intervalStart := 0;
intervalEnd := 0;
intervalStart := intervalStart + (i-1)*intervalMins;
intervalEnd := intervalEnd + (i*intervalMins)-1;
--dbms_output.put_line(intervalStart || ' - ' || intervalEnd);
insert into intervalTable
(
row_id,
intStart,
intEnd,
intervalName
)
values(i, intervalStart, intervalEnd, (intervalStart || ' - ' || intervalEnd));
end loop;
end;

Answer 1

I think you want something like this:
with freq_data as (
select level as id, (level-1)*30 as start_interval, ((level-1)*30) + 29 as end_interval, (level-1)*30 || ' - ' || to_char(((level-1)*30) + 29) as label
from dual
connect by level <= 30
order by level
)
select * from freq_data;
Output
ID START_INTERVAL END_INTERVAL LABEL
1 0 29 0 - 29
2 30 59 30 - 59
3 60 89 60 - 89
4 90 119 90 - 119
5 120 149 120 - 149
6 150 179 150 - 179
7 180 209 180 - 209
8 210 239 210 - 239
9 240 269 240 - 269
10 270 299 270 - 299
11 300 329 300 - 329
12 330 359 330 - 359
13 360 389 360 - 389
14 390 419 390 - 419
15 420 449 420 - 449
16 450 479 450 - 479
17 480 509 480 - 509
18 510 539 510 - 539
19 540 569 540 - 569
20 570 599 570 - 599
21 600 629 600 - 629
22 630 659 630 - 659
23 660 689 660 - 689
24 690 719 690 - 719
25 720 749 720 - 749
26 750 779 750 - 779
27 780 809 780 - 809
28 810 839 810 - 839
29 840 869 840 - 869
30 870 899 870 - 899
An example using the above in a join query:
create table my_test
(
num number
-- other important data ...
);
-- insert some random numbers
insert into my_test
select trunc(DBMS_RANDOM.VALUE(0,900))
from dual
connect by level <= 10;
commit;
Now joining to get the label for each num field:
with freq_data as (
select level as id, (level-1)*30 as start_interval, ((level-1)*30) + 29 as end_interval, (level-1)*30 || ' - ' || to_char(((level-1)*30) + 29) as label
from dual
connect by level <= 30
order by level
)
select t.num, d.label
from my_test t
left join freq_data d ON (t.num between d.start_interval and d.end_interval);
Output:
NUM LABEL
64 60 - 89
73 60 - 89
128 120 - 149
154 150 - 179
267 240 - 269
328 300 - 329
550 540 - 569
586 570 - 599
745 720 - 749
795 780 - 809