how to change positive value to negative

Question

I have Input parameter

@SMSSessionTimeout AS INT

Suppose @SMSSessionTimeout = 300

While using inside begin...end, I want to make it negative value. Like @SMSSessionTimeout = -300

Thanks in advance.

Answer 1

Multiply it by -1

SELECT @SMSSessionTimeout = @SMSSessionTimeout * -1;

Answer 2

Prefix the value with a minus sign.

SET @SMSSessionTimeout = -@SMSSessionTimeout