SIGN

Syntax

SIGN(X)

Purpose

You can call SIGN(X) to return the sign of the argument. The value returned depends on whether X is a negative number, zero, or a positive number. Floating-point numbers and hexadecimal numbers are supported. Return values:

• If X is a negative number, -1 is returned.

• If X is zero, 0 is returned.

• If X is a positive number, 1 is returned.

The function also supports comparison operation. The comparison result is converted to a numeric value. The result is 1 (TRUE) or 0 (FALSE).

If you enter NULL, the return value is NULL.

Examples

obclient> SELECT SIGN(-32), SIGN(0), SIGN(234);
+-----------+---------+-----------+
 SIGN(-32)  SIGN(0)  SIGN(234) 
+-----------+---------+-----------+
        -1        0          1 
+-----------+---------+-----------+
1 row in set (0.01 sec)

obclient> SELECT SIGN(NULL),SIGN(FALSE),SIGN(0X01);
+------------+-------------+------------+
 SIGN(NULL)  SIGN(FALSE)  SIGN(0X01) 
+------------+-------------+------------+
       NULL            0           1 
+------------+-------------+------------+
1 row in set (0.00 sec)