Need to generate n rows based on a value in a column

Question

I have the following table

TABLE A

ID | QUANTITY
------------
1  | 3
2  | 2

What I need is

TABLE B

ID | Ref No.
------------
1  | MyRef1
1  | MyRef2
1  | MyRef3
2  | AnotherRef1
2  | AnotherRef2

i.e. I need to generate Table B with the same number of rows as the quantity in A with an ascending ref no. on each row.

I can do it with cursors or UDFs but is there a more graceful solution?

Answer 1

I'll assume

1. MyRef etc is a column in TableA
2. You have a numbers table

Something like:

SELECT * INTO #TableA
FROM
 (
    SELECT  1 AS ID, 3 AS QUANTITY, 'MyRef' AS refColumn
    UNION ALL
    SELECT 2, 2, 'AnotherRef'
) T


;WITH Nbrs ( Number ) AS (
    SELECT 1 UNION ALL
    SELECT 1 + Number FROM Nbrs WHERE Number < 99
)
SELECT
   A.ID, A.refColumn + CAST(N.Number AS varchar(10))
FROM
   #TableA A
   JOIN
   Nbrs N ON N.Number <= A.QUANTITY