Oracle 從 dual 表中查詢返回多行記錄

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

 

 

同時查詢出十條數據

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

 

按照這個特性計算兩個日期之間的工作日：

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');