sql - How can I expand out a row into multiple row result set?

Question

I have a table that I'm trying to break out each row into one or more rows based on the second column value. Like this:

table (id, pcs):
ABC   3
DEF   1
GHJ   4

query result (id, pcs_num):
ABC   1
ABC   2
ABC   3
DEF   1
GHJ   1
GHJ   2
GHJ   3
GHJ   4

I'm writing this as a sproc in SQL server 2008. My best solution is to use a cursor and add [pcs] number of rows to a temp table for each row in the table. Is seems like there must be a simpler solution than this that I am missing. Thanks.

Answer 1

You can use a recursive CTE:

;WITH CTE AS
(
    SELECT *
    FROM YourTable
    UNION ALL 
    SELECT id, pcs-1
    FROM CTE
    WHERE pcs-1 >= 1
)
SELECT *
FROM CTE
ORDER BY id, pcs
OPTION(MAXRECURSION 0)

Here is a demo for you to try.