oracle中sign函数详解

在Oracle/PLSQL中, sign 函数返回一个数字的正负标志.

语法如下：sign( number )

number 要测试标志的数字.

If number < 0, then sign returns -1.
If number = 0, then sign returns 0.
If number > 0, then sign returns 1.

应用于:

• Oracle 8i, Oracle 9i, Oracle 10g, Oracle 11g

例如:

sign(-23)	would return -1
sign(-0.001)	would return -1
sign(0)	would return 0
sign(0.001)	would return 1
sign(23)	would return 1
sig(23.601)	would return 1

 

 

示例：
一、select sign( 100 ),sign(- 100 ),sign( 0 ) from dual;

　　SIGN(100) SIGN(-100) SIGN(0)
　　-----------------------------------------------------------
　　1 -1 0

二、a=10，b=20 
　　则sign(a-b)返回-1