sql 的FLOOR、ROUND、CEIL、TRUNC

返回大于或等于x的最大整数:
SQL> select ceil(23.33) from dual;

CEIL(23.33)
-----------
24

返回等于或小于x的最大整数:
SQL> select floor(23.33) from dual;

FLOOR(23.33)
------------
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;

ROUND(23.33)
------------
23

返回截尾到y位小数的x值:trunc(x,[y])
SQL> select trunc(23.33) from dual;

TRUNC(23.33)
------------
23