MySQL语法：
SELECT
CASE WHEN a < 1 THEN '' ELSE CONCAT('1*',a,'=',a*1) END AS '1',
CASE WHEN a < 2 THEN '' ELSE CONCAT('2*',a,'=',a*2) END AS '2',
CASE WHEN a < 3 THEN '' ELSE CONCAT('3*',a,'=',a*3) END AS '3',
CASE WHEN a < 4 THEN '' ELSE CONCAT('4*',a,'=',a*4) END AS '4',
CASE WHEN a < 5 THEN '' ELSE CONCAT('5*',a,'=',a*5) END AS '5',
CASE WHEN a < 6 THEN '' ELSE CONCAT('6*',a,'=',a*6) END AS '6',
CASE WHEN a < 7 THEN '' ELSE CONCAT('7*',a,'=',a*7) END AS '7',
CASE WHEN a < 8 THEN '' ELSE CONCAT('8*',a,'=',a*8) END AS '8',
CASE WHEN a < 9 THEN '' ELSE CONCAT('9*',a,'=',a*9) END AS '9'
FROM (
SELECT 1 AS a
UNION ALL
SELECT 2
UNION ALL
SELECT 3
UNION ALL
SELECT 4
UNION ALL
SELECT 5
UNION ALL
SELECT 6
UNION ALL
SELECT 7
UNION ALL
SELECT 8
UNION ALL
SELECT 9
) AS t1
Oracle语法：
SELECT
CASE WHEN a < 1 THEN '' ELSE '1*'||a||'='||a*1 END AS "1",
CASE WHEN a < 2 THEN '' ELSE '2*'||a||'='||a*2 END AS "2",
CASE WHEN a < 3 THEN '' ELSE '3*'||a||'='||a*3 END AS "3",
CASE WHEN a < 4 THEN '' ELSE '4*'||a||'='||a*4 END AS "4",
CASE WHEN a < 5 THEN '' ELSE '5*'||a||'='||a*5 END AS "5",
CASE WHEN a < 6 THEN '' ELSE '6*'||a||'='||a*6 END AS "6",
CASE WHEN a < 7 THEN '' ELSE '7*'||a||'='||a*7 END AS "7",
CASE WHEN a < 8 THEN '' ELSE '8*'||a||'='||a*8 END AS "8",
CASE WHEN a < 9 THEN '' ELSE '9*'||a||'='||a*9 END AS "9"
FROM (
SELECT LEVEL a FROM DUAL connect BY LEVEL<10
)
