How to duplicate table row based on column value in Teradata?

Question

Can someone help this task? If I have one table as below in Teradata:

caseid	content	repeat
id1	row1	2
id2	row2	3

I want to build a new table based on the repeat value as below. How should I do?

caseid	content	repeat	groupid
id1	row1	2	1
id1	row1	2	2
id2	row2	3	1
id2	row2	3	2
id2	row2	3	3

Thanks!

Answer 1

Teradata proprietary EXPAND ON syntax creates time series and can be used for this task:

SELECT t.*
   -- convert period back to int
  ,End(pd) - Current_Date AS groupid
FROM mytable AS t
-- works on date/time only -> convert int to period
EXPAND ON PERIOD(Current_Date, Current_Date + repeat) AS pd 

Answer 2

you can do it using recursive cte :

with recursive cte as (
select * , 1 groupid from cases 
union all 
select caseid ,content, repeat, groupid + 1 groupid
from cte 
where groupid  < repeat
)

select  * from cte
order by caseid

caseid | content | repeat | groupid
-----: | :------ | -----: | ------:
     1 | row1    |      2 |       1
     1 | row1    |      2 |       2
     2 | row2    |      3 |       1
     2 | row2    |      3 |       2
     2 | row2    |      3 |       3

db<>fiddle here