SIGN
This function returns 1 if the argument is positive, -1 if it is negative, and 0 if it is 0.
Syntax
SIGN ( expression )
Arguments
expression: any valid numeric expression.
Return Type
Integer.
Examples
SELECT SIGN(6), SIGN(-6), SIGN(0); **** +---------+----------+---------+ | SIGN(6) | SIGN(-6) | SIGN(0) | +---------+----------+---------+ | 1 | -1 | 0 | +---------+----------+---------+