簡単に直積演算を体感するスクリプト

おまけです。
テーブルとか作らずに、簡単に直積演算を体感するスクリプトです。

標準SQL編

select concat(t1.decitem,'×',t2.decitem,' = ',t1.decitem * t2.decitem ) from
(
select 1 as decitem
union
select 2
union
select 3
union
select 4
union
select 5
union
select 6
union
select 7
union
select 8
union
select 9
) t1
cross join
(
select 1 as decitem
union
select 2
union
select 3
union
select 4
union
select 5
union
select 6
union
select 7
union
select 8
union
select 9
) t2
on 1=1
order by 1;

結果です。

1×1 = 1
1×2 = 2
1×3 = 3
1×4 = 4
1×5 = 5
1×6 = 6
1×7 = 7
1×8 = 8
1×9 = 9
2×1 = 2
2×2 = 4
2×3 = 6
2×4 = 8
2×5 = 10
2×6 = 12
2×7 = 14
2×8 = 16
2×9 = 18
3×1 = 3
3×2 = 6
3×3 = 9
3×4 = 12
3×5 = 15
3×6 = 18
3×7 = 21
3×8 = 24
3×9 = 27
4×1 = 4
4×2 = 8
4×3 = 12
4×4 = 16
4×5 = 20
4×6 = 24
4×7 = 28
4×8 = 32
4×9 = 36
5×1 = 5
5×2 = 10
5×3 = 15
5×4 = 20
5×5 = 25
5×6 = 30
5×7 = 35
5×8 = 40
5×9 = 45
6×1 = 6
6×2 = 12
6×3 = 18
6×4 = 24
6×5 = 30
6×6 = 36
6×7 = 42
6×8 = 48
6×9 = 54
7×1 = 7
7×2 = 14
7×3 = 21
7×4 = 28
7×5 = 35
7×6 = 42
7×7 = 49
7×8 = 56
7×9 = 63
8×1 = 8
8×2 = 16
8×3 = 24
8×4 = 32
8×5 = 40
8×6 = 48
8×7 = 56
8×8 = 64
8×9 = 72
9×1 = 9
9×2 = 18
9×3 = 27
9×4 = 36
9×5 = 45
9×6 = 54
9×7 = 63
9×8 = 72
9×9 = 81

こんな感じです。

Oracleの書き方がこちら。

select t1.dec||'×'||t2.dec||' = '||t1.dec * t2.dec from
(
select 1 as dec from dual
union
select 2 from dual
union
select 3 from dual
union
select 4 from dual
union
select 5 from dual
union
select 6 from dual
union
select 7 from dual
union
select 8 from dual
union
select 9 from dual
) t1,
(
select 1 as dec from dual
union
select 2 from dual
union
select 3 from dual
union
select 4 from dual
union
select 5 from dual
union
select 6 from dual
union
select 7 from dual
union
select 8 from dual
union
select 9 from dual
) t2
;