SQLServer和Oracle的常用函数对比.doc

SQLServer和Oracle的常用函数对比(实用)---------数学函数绝对值S:selectabs(-1)valueO:selectabs(-1)valuefromdual取整(大)S:selectceiling(-)valueO:selectceil(-)valuefromdual取整(小)S:selectfloor(-)valueO:selectfloor(-)valuefromdual取整(截取)S:selectcast(-)valueO:selecttrunc(-)valuefromdual四舍五入S:selectround(,4):selectround(,4):selectExp(1)**********O:selectExp(1):selectlog(**********)value1O:selectln(**********)valuefromdual;1取10为底对数S:selectlog10(10)value1O:selectlog(10,10)valuefromdual;1取平方S:selectSQUARE(4)value16O:selectpower(4,2)valuefromdual16取平方根S:selectSQRT(4)value2O:selectSQRT(4)valuefromdual2求任意数为底的幂S:selectpower(3,4)value81O:selectpower(3,4)valuefromdual81取随机数S:selectrand()valueO:(0,1)valuefromdual;取符号S:selectsign(-8)value-1O:selectsign(-8)valuefromdual-1----------数学函数圆周率S:SELECTPI():不知道sin,cos,tan参数都以弧度为单位例如:selectsin(PI()/2)value得到1(SQLServer)Asin,Acos,Atan,Atan2返回弧度弧度角度互换(SQLServer,Oracle不知道)DEGREES:弧度-〉角度RADIANS:角度-〉弧度---------数值间比较求集合最大值S:selectmax(value)valuefrom(select1valueunionselect-2valueunionselect4valueunionselect3value)aO:selectgreatest(1,-2,4,3)valuefromdual求集合最小值S:selectmin(value)valuefrom(select1valueunionselect-2valueunionselect4valueunionselect3value)aO:selectleast(1,-2,4,3)valuefromdual如何