关于处理小数点位数的几个oracle函数()1. 取四舍五入的几位小数select round(1.2345, 3) from dual;结果:1.2352. 保留两位小数，
关于处理小数点位数的几个Oracle函数()
1. 取四舍五入的几位小数
select round(1.2345, 3) from dual;
结果:1.235
2. 保留两位小数，只舍
select trunc(1.2345, 2) from dual;
结果:1.23
select trunc(1.2399, 2) from dual;
结果:1.23
3.取整数
返回大于或等于x的最大整数:
SQL> select ceil(23.33) from dual;
结果: 24
返回等于或小于x的最大整数:
SQL> select floor(23.33) from dual;
结果: 23
返回舍入到小数点右边y位的x值:rcund(x,[y])
SQL> select round(23.33) from dual;
结果: 23
返回截尾到y位小数的x值:trunc(x,[y])
SQL> select trunc(23.33) from dual;
结果: 23
格式化数字
The following are number examples for the to_char function.
to_char(1210.73, '9999.9') would return '1210.7'
to_char(1210.73, '9,999.99') would return '1,210.73'
to_char(1210.73, '$9,999.00') would return '$1,210.73'
to_char(21, '000099') would return '000021'
to_char函数特殊用法
to_char(sysdate,'d') 每周第几天
to_char(sysdate,'dd') 每月第几天
to_char(sysdate,'ddd') 每年第几天
to_char(sysdate,'ww') 每年第几周
to_char(sysdate,'mm') 每年第几月
to_char(sysdate,'q') 每年第几季
to_char(sysdate,'yyyy') 年
比如要找某个时间为每周第几天就可以
SQL> select to_char(to_date('20070101','yyyymmdd'),'d') from dual;
