按照我的想法,应用矩阵之间的交叉关系,如果两个表中有2条记录的话,那两个表交叉就是2*2=4 如果两个表中有4条记录的话,那两个表交叉就是4*4=16 如果两个表中有16录的话,那两个表交叉就是16*16=256脚本如下:select rownum from ( select aa.a from ( select a.a from (select '1' as a,'2' as b from dual union all select '1' as a,'2' as b from dual ) a, (select '1' as a,'2' as b from dual union all select '1' as a,'2' as b from dual ) b ) aa,( select a.a from (select '1' as a,'2' as b from dual union all select '1' as a,'2' as b from dual ) a, (select '1' as a,'2' as b from dual union all select '1' as a,'2' as b from dual ) b ) bb ) aaa, ( select aa.a from ( select a.a from (select '1' as a,'2' as b from dual union all select '1' as a,'2' as b from dual ) a, (select '1' as a,'2' as b from dual union all select '1' as a,'2' as b from dual ) b ) aa,( select a.a from (select '1' as a,'2' as b from dual union all select '1' as a,'2' as b from dual ) a, (select '1' as a,'2' as b from dual union all select '1' as a,'2' as b from dual ) b ) bb)bbb where rownum<101
取得 1。。100
可能还有2。。200这样的情况,所以要写成SELECT
如果两个表中有4条记录的话,那两个表交叉就是4*4=16
如果两个表中有16录的话,那两个表交叉就是16*16=256脚本如下:select rownum from (
select aa.a from (
select a.a from (select '1' as a,'2' as b from dual union all
select '1' as a,'2' as b from dual
) a,
(select '1' as a,'2' as b from dual union all
select '1' as a,'2' as b from dual
) b
) aa,(
select a.a from (select '1' as a,'2' as b from dual union all
select '1' as a,'2' as b from dual
) a,
(select '1' as a,'2' as b from dual union all
select '1' as a,'2' as b from dual
) b
) bb
) aaa,
(
select aa.a from (
select a.a from (select '1' as a,'2' as b from dual union all
select '1' as a,'2' as b from dual
) a,
(select '1' as a,'2' as b from dual union all
select '1' as a,'2' as b from dual
) b
) aa,(
select a.a from (select '1' as a,'2' as b from dual union all
select '1' as a,'2' as b from dual
) a,
(select '1' as a,'2' as b from dual union all
select '1' as a,'2' as b from dual
) b
) bb)bbb where rownum<101
然后用rownum控制就好了
有现成的seq不用,为什么要写这么麻烦的语句?
不明白
你说的我早就想过了,可以使用系统表来做,一般系统表会随时间的增加而增加,能到100W的条数,不过要是你们知道更好的方法也可以晚些时候告诉我,谢谢