MySQL trigger to set column to max + 1 not working
I'm having difficulty writing a trigger that sets the rank column to the max rank value plus 1 for a group of user ids. Maybe the code would be more helpful than my description:
CREATE TABLE `saved_listing` (
`saved_listing_id` int(10) NOT NULL auto_increment,
`user_id` int(10) NOT NULL default '0',
`listing_id` int(10) NOT NULL default '0',
`listing_ty` varchar(10) NOT NULL default '',
`notes` text NULL,
`rank` int(10) NOT NULL default '0',
`modify_by` int(10) NOT NULL default '1',
`modify_dt` timestamp NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
`create_by` int(10) NOT NULL default '1',
`create_dt` datetime NOT NULL default '0000-00-00 00:00:00',
`active` enum('Yes','No') NOT NULL default 'No',
PRIMARY KEY (`saved_listing_id`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=0 ;
Here's my trigger code:
CREATE TRIGGER ins_saved_listing BEFORE INSERT ON saved_listing
FOR EACH ROW BEGIN
SET NEW.create_dt = NOW();
SET NEW.rank = (SELECT MAX(rank) + 1 FROM saved_listing WHERE user_id = NEW.user_id);
END
Here's the error message I'm getting:
1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 3
Any help would be greatly开发者_运维问答 appreciated. I don't have much experience writing triggers.
MySQL Server version: 5.1.49-3~bpo50+1
That is because mysql sees ;
(the delimiter) and breaks the execution of CREATE TRIGGER
Try to change to:
delimiter |
CREATE TRIGGER ins_saved_listing BEFORE INSERT ON saved_listing
FOR EACH ROW BEGIN
SET NEW.create_dt = NOW();
SET NEW.rank = (SELECT MAX(rank) + 1 FROM saved_listing WHERE user_id = NEW.user_id);
END;
|
delimiter ;
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