这可以简化吗?
SELECT
*
FROM
(
SELECT * FROM (SELECT 1 AS Quarter) AS Q1
UNION
SELECT * FROM (SELECT 2 AS Quarter) AS Q2
UNION
SELECT * FROM (SELECT 3 AS Quarter) AS Q3
UNION
SELECT * FROM (SELECT 4 AS Quarter) AS Q4
) AS IQ1
CROSS JOIN
(
SELECT * FROM (SELECT 2000 AS Y) AS Q1
UNION
SELECT * FROM (SELECT 2001 AS Y) AS Q2
) AS IQ2