round函数怎么用oracle,oracle round函数的使用方法

round(input_value,decimal_places_of_precision),例如：

SQL>   select   round(1234.5678,4)   from   dual;

ROUND(1234.5678,4)

------------------

1234.5678

SQL>   select   round(1234.5678,3)   from   dual;

ROUND(1234.5678,3)

------------------

1234.568

SQL>   select   round(1234.5678,2)   from   dual;

ROUND(1234.5678,2)

------------------

1234.57

SQL>   select   round(1234.5678,1)   from   dual;

ROUND(1234.5678,1)

------------------

1234.6

SQL>   select   round(1234.5678,0)   from   dual;

ROUND(1234.5678,0)

------------------

1235

SQL>   select   round(1234.5678,-1)   from   dual;

ROUND(1234.5678,-1)

-------------------

1230

SQL>   select   round(1234.5678,-2)   from   dual;

ROUND(1234.5678,-2)

-------------------

1200

SQL>   select   round(1234.5678,-3)   from   dual;

ROUND(1234.5678,-3)

-------------------

1000