WEB开发网
开发学院数据库MSSQL Server MS SQL Server和Oracle的常用函数对比 阅读

MS SQL Server和Oracle的常用函数对比

 2007-11-11 11:18:31 来源:WEB开发网   
核心提示:1.绝对值 S:select abs(-1) valueO:select abs(-1) value from dual2.取整(大) S:select ceiling(-1.001) value O:select ceil(-1.001) value from dual3.取整(小) S:select floor(-

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(大型网站数据库平台)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 4 value
  union
  select 3 value)a

O:select least(1,-2,4,3) value from dual

20.如何处理null值(F2中的null以10代替)
  S:select F1,IsNull(F2,10) value from Tbl
  O:select F1,nvl(F2,10) value from Tbl

--------数值间比较

1 2 3  下一页

Tags:MS SQL Server

编辑录入:coldstar [复制链接] [打 印]
赞助商链接