make 3 rows, 1 column from 1 row 3 colums

Question

I have following table in db2:

id	person 1	person 2	person 3
1	10	12	15

I now want to make a query that returns the following:

id	person
1	10
1	12
1	15

how can I do this in db2?

Thanks in advance!

Answer 1

It's more efficiently not to scan the same potentially large table multiple times.
Try this:

SELECT T.ID, V.PERSON
FROM MYTAB T, TABLE (VALUES T.PERSON1, T.PERSON2, T.PERSON3) V (PERSON);

Answer 2

Use a UNION:

select id, person1 as person
from the_table
union all 
select id, person2
from the_table
union all 
select id, person3
from the_table