Oracle 从 dual 表中查询返回多行记录

 select 1 as id,'是' as text from dual
 union all
 select 0 as id ,'否' as text from dual

 

 

同时查询出十条数据

select * from dual connect by 0 + level <= 10;

 

按照这个特性计算两个日期之间的工作日：

select days, week from (select to_date('2010-08-01', 'YYYY-MM-DD') + level - 1 as days, to_char(to_date('2010-08-01', 'YYYY-MM-DD') + level - 1, 'day') as week from dual connect by to_date('2010-08-30', 'YYYY-MM-DD') - level + 1 >= to_date('2010-08-01', 'YYYY-MM-DD')) where week not in('saturday','sunday');