1-2000的素数

select c1.c,       sum(case             when mod(c1.c, c2.c) = 0 then              1             else              0           end)  from (select level c from dual connect by level <= 2000) c1,       (select level + 1 c from dual connect by level <= 2000 - 1) c2 where c1.c > c2.c group by c1.chaving sum(case when mod(c1.c, c2.c) = 0 then 1 else 0 end) = 0