select SYSDATE from dual;
2、用作计算器
select 1+2 from dual;
参考：http://www.cnblogs.com/qiangqiang/archive/2010/10/15/1852229.html
select SYSDATE from dual;
select 1+2 from dual;
参考：http://www.cnblogs.com/qiangqiang/archive/2010/10/15/1852229.html
