round函数用来作四舍五入操作, select round(5555.6666,2),round(5555.6666,-2.6),round(5555.6666) from dual;
返回: 5555.67 , 5600 , 5556
返回: 5555.67 , 5600 , 5556
trunc函数用来截取,只不过不作四舍五入操作
select trunc(5555.66666,2.1),trunc(5555.66666,-2.6),trunc(5555.033333) from dual;
返回:5555.66 5500 5555
返回:5555.66 5500 5555