mssql server 2005 数学函数
1.求绝对值
abs()
select fweight-50,abs(fweight-50),abs(-5.38) from t_person
2.求幂
power(x,y) 用来计算x的y次幂
select fweight,power(fweight,-0.5),power(fweight,2),
power(fweight,3),power(fweight,4) from t_person
select power(2,2)
3.求平方根
sqrt()
select fweight,sqrt(fweight) from t_person
4. 求随机数
rand() 支持有参数，也可以没参数
select rand()
select rand(123)
5.舍入到最大整数
ceiling()
select fname,fweight,ceiling(fweight),ceiling(fweight*-1) from t_person
6.舍入到最小整数
floor()
select fname,fweight,floor(fweight),floor(fweight*-1) from t_person
7.四舍五入
round()
round(m,d) m为待进行四舍五入的数值，d为计算精度，也就是四舍五入时保留的小数位数
d为0表示不保留小数位，d为负值表示在整数部分进行四舍五入。
select fname,fweight,round(fweight,1),round(fweight*-1,0),round(fweight,-1) from t_person
8.求正弦值
sin()
select fname,fweight,sin(fweight)from t_person
9.求余弦值
cos()
select fname,fweight,cos(fweight) from t_person
10.求反正弦
asin()
select fname,fweight,asin(1/fweight) from t_person
11.求反余弦
acos()
select fname,fweight,acos(1/fweight) from t_person
12.求正切值
tan()
select fname,fweight,tan(fweight) from t_person
13.求反正切值
atan()
select fname,fweight,atan(fweight) from t_person
14.求两个变量的反正切
atn2(x,y) 类似于计算y/x的反正切
select fname,fweight,atn2(fweight,2) from t_person
15.求余切
cot()
select fname,fweight,cot(fweight) from t_person
16.求圆周率π值
pi()
select fname,fweight,fweight*pi(),pi() from t_person
17.弧度制转换为角度制
degrees() 结果的精确度与参数有关
select degrees(pi()),degrees(3.0),degrees(3)
18.角度制转换为弧度制
radians() 结果的精确度与参数有关
select radians(180),radians(180.0)
19.求符号
sign() 返回一个数值的符号，如果数值大于0则返回1，
如果数值等于0则返回0，如果数值小于0则返回-1.
结果的精确度与参数有关
select fname,fweight-48.68,sign(fweight-48.68),sign(1),sign(1.000) from t_person
20.求整除余数 %
select fname,fweight,fweight%5 from t_person
21.求自然对数
log()
select fname,fweight,log(fweight),log(1.00) from t_person
22.求以10为底的对数
log10()
select fname,fweight,log10(fweight),log10(100) from t_person
ps：
主要参照《程序员的sql金典》
实例有所改动。
t_person表的创建
复制代码 代码如下:
create table t_person
(
fidnumber varchar(20),
fname varchar(20),
fbirthday datetime,
fregday datetime,
fweight numeric(10,2),
)