Oracle commonly used numeric functions

-- 返回绝对值 
select abs(100),abs(-100) from dual;
-- 返回正负值 
select sign(100),sign(-100),sign(0) from dual;
-- 返回较大的最小整数 
select ceil(3.1),ceil(2.8 1.3),ceil(0) from dual;
-- 返回较小的最大整数
select floor(3.1),floor(2.8 1.3),floor(0) from dual;
-- 返回X的Y次幂 
select power(2.5,2),power(1.5,0),power(20,-1) from dual;
-- 返回常量e的y次幂 exp
select exp(3),exp(0),exp(-3) from dual;
-- 返回以X为底数的y的对数 log
select power(4,2),log(16,2),1/log(16,4) from dual;
-- 返回以常量e为底的y的对数 ln
select exp(3),exp(-3),ln(20.0855369),ln(0.049787068) from dual;
-- 返回x除以y的余数 
select mod(23,8),mod(24,8) from dual;
-- 返回四舍五入后的值 
select round(5555.6666,2.1),round(5555.6666,-2.6),round(5555.6666) from dual;
-- 返回截取后的值 
select trunc(5555.66666,2.1),trunc(5555.66666,-2.6),trunc(5555.033333) from dual;
-- 返回X的平方根 
select sqrt(64),sqrt(10) from dual;