一句SQL实现输出九九乘法表

      select r1 || '*' || r1 || '=' || r1 * r1 A,       decode(r2, '', '', r2 || '*' || r1 || '=' || r2 * r1) b,       decode(r3, '', '', r3 || '*' || r1 || '=' || r3 * r1) C,       decode(r4, '', '', r4 || '*' || r1 || '=' || r4 * r1) D,       decode(r5, '', '', r5 || '*' || r1 || '=' || r5 * r1) E,       decode(r6, '', '', r6 || '*' || r1 || '=' || r6 * r1) F,       decode(r7, '', '', r7 || '*' || r1 || '=' || r7 * r1) G,       decode(r8, '', '', r8 || '*' || r1 || '=' || r8 * r1) H,       decode(r9, '', '', r9 || '*' || r1 || '=' || r9 * r1) Ifrom   (select level r1,               lag(level, 1) over(order by level) r2,               lag(level, 2) over(order by level) r3,               lag(level, 3) over(order by level) r4,               lag(level, 4) over(order by level) r5,               lag(level, 5) over(order by level) r6,               lag(level, 6) over(order by level) r7,               lag(level, 7) over(order by level) r8,               lag(level, 8) over(order by level) r9        from   dual        connect by level < 10)