Trying to understand simple math functions in MySQL

[kahodges]

MySQL version 5.1.30.

 

I have a field that I'm trying to update and add a number to, and then have it update to the new total and display the sum in that same field. Is this possible?

 

 

 

Tried:

SELECT avail_vacation FROM vacation WHERE employee = employee1 + 30;
UPDATE vacation.avail_vacation WHERE employee = "employee1" + 30;

Table:
CREATE TABLE IF NOT EXISTS `vacation` (
  `id` int(6) NOT NULL AUTO_INCREMENT,
  `employee` varchar(75) COLLATE utf8_unicode_ci NOT NULL,
  `avail_vacation` smallint(6) NOT NULL,
  `added` int(4) NOT NULL,
  `used` int(4) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `employee` (`employee`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=2 ;

 

Thanks.

[brianlange]

Your update statement needs editing. Update `vacation` set  avail_vacation = `vacation` + 30 where employee = employee1 

[kahodges]

Update `vacation` set  avail_vacation = `avail_vacation` + 30 where employee = "employee1";  

 

That worked. Thank you.