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
create table T_Person
(
FIdNumber varchar(20),
FName varchar(20),
FBirthDay datetime,
FRegDay datetime,
FWeight numeric(10,2),
)