Question

I need to rewrite this so it does not cause an overrun on my db. I need to rewrite it so it does not use a cursor.

Thank you.

Answer 1

UPDATED Here’s some test data:

CREATE TABLE #TableB(SKU INT, BeginYear INT, EndYear INT, OptionA VARCHAR(10), OptionB VARCHAR(10))

INSERT INTO #TableB(SKU, BeginYear, EndYear, OptionA, OptionB)
VALUES  (1, 1920, 1950, 'option1', 'option1'),
        (1, 1980, 2001, 'option1', 'option2'),
        (1, 1940, 1952, 'option1', 'option1'), --overlapping years
        (2, 2001, 2005, 'option1', 'option1')

CREATE TABLE #TableA(SKU INT, OptionA VARCHAR(10), OptionB VARCHAR(10), Years INT)

Then you can try a recursive CTE:

;WITH CTE AS
(
    SELECT DISTINCT SKU, BeginYear, EndYear, OptionA, OptionB
    FROM #TableB
    UNION ALL
    SELECT SKU, BeginYear+1, EndYear, OptionA, OptionB
    FROM CTE 
    WHERE BeginYear < EndYear
)  
INSERT INTO #TableA(SKU, OptionA, OptionB, Years)
SELECT DISTINCT SKU, OptionA, OptionB, BeginYear
FROM CTE 
OPTION(MAXRECURSION 0)

SELECT *
FROM #TableA
ORDER BY SKU, OptionA, OptionB, Years

Here there’s no cartesian product.