hive - split a row into multiple rows between the range of values - sql

Question

I have a table below and would like to split the rows by the range from start to end columns.
i.e id and value should repeat for each value between start & end(both inclusive)
--------------------------------------
id | value | start | end
--------------------------------------
1 | 5 | 1 | 4
2 | 8 | 5 | 9
--------------------------------------
Desired output
--------------------------------------
id | value | current
--------------------------------------
1 | 5 | 1
1 | 5 | 2
1 | 5 | 3
1 | 5 | 4
2 | 8 | 5
2 | 8 | 6
2 | 8 | 7
2 | 8 | 8
2 | 8 | 9
--------------------------------------
I can write my own UDF in java/python to get this result but would like to check if I can implement in Hive SQL using any existing hive UDFs
Thanks in advance.

Answer 1

This can be accomplished with a recursive common table expression, which Hive doesn't support.
One option is to create a table of numbers and use it to generate rows between start and end.
create table numbers
location 'hdfs_location' as
select row_number() over(order by somecolumn) as num
from some_table --this can be any table with the desired number of rows
;
--Join it with the existing table
select t.id,t.value,n.num as current
from tbl t
join numbers n on n.num>=t.start and n.num<=t.end

Answer 2

You can do using posexplode() UDF.
WITH
data AS (
SELECT 1 AS id, 5 AS value, 1 AS start, 4 AS `end`
UNION ALL
SELECT 2 AS id, 8 AS value, 5 AS start, 9 AS `end`
)
SELECT distinct id, value, (zr.start+rge.diff) as `current`
FROM data zr LATERAL VIEW posexplode(split(space(zr.`end`-zr.start),' ')) rge as diff, x
Here is its Output:
+-----+--------+----------+--+
| id | value | current |
+-----+--------+----------+--+
| 1 | 5 | 1 |
| 1 | 5 | 2 |
| 1 | 5 | 3 |
| 1 | 5 | 4 |
| 2 | 8 | 5 |
| 2 | 8 | 6 |
| 2 | 8 | 7 |
| 2 | 8 | 8 |
| 2 | 8 | 9 |
+-----+--------+----------+--+