SQLServer和Oracle的常用函数对比

SQLServer和Oracle的常用函数对比
 
1.绝对值
S:select abs(-1) value
O:select abs(-1) value from dual
 
2.取整(大)
S:select ceiling(-1.001) value
O:select ceil(-1.001) value from dual
 
3.取整（小）
S:select floor(-1.001) value
O:select floor(-1.001) value from dual
 
4.取整（截取）
S:select cast(-1.002 as int) value
O:select trunc(-1.002) value from dual
 
5.四舍五入
S:select round(1.23456,4) value 1.23460
O:select round(1.23456,4) value from dual 1.2346
 
6.e为底的幂
S:select Exp(1) value 2.7182818284590451
O:select Exp(1) value from dual 2.71828182
 
7.取e为底的对数
S:select log(2.7182818284590451) value 1
O:select ln(2.7182818284590451) value from dual; 1
 
8.取10为底对数
S:select log10(10) value 1
O:select log(10,10) value from dual; 1
 
9.取平方
S:select SQUARE(4) value 16
O:select power(4,2) value from dual 16
 
10.取平方根
S:select SQRT(4) value 2
O:select SQRT(4) value from dual 2
 
11.求任意数为底的幂
S:select power(3,4) value 81
O:select power(3,4) value from dual 81
 
12.取随机数
S:select rand() value
O:select sys.dbms_random.value(0,1) value from dual;
 
13.取符号
S:select sign(-8) value -1
O:select sign(-8) value from dual -1
----------数学函数
 
14.圆周率
S:SELECT PI() value 3.1415926535897931
O:不知道
 
15.sin,cos,tan 参数都以弧度为单位
例如：select sin(PI()/2) value 得到1（SQLServer）
 
16.Asin,Acos,Atan,Atan2 返回弧度
 
17.弧度角度互换(SQLServer，Oracle不知道)
DEGREES：弧度-〉角度
RADIANS：角度-〉弧度
 
---------数值间比较
 
18. 求集合最大值
S:select max(value) value from
(select 1 value
union
select -2 value
union
select 4 value
union
select 3 value)a
 
O:select greatest(1,-2,4,3) value from dual
 
19. 求集合最小值
S:select min(value) value from
(select 1 value
union
select -2 value
union
select