可以这样
select * from dept where deptno in('10')
union all
selecr * from dept where deptno in('10')
select * from dept where deptno in('10')
union all
selecr * from dept where deptno in('10')
select a.* from (select * from dept where deptno='10') a,(select rowid from all_tables where rownum<=2);