Question

Table: items
Create Table:

CREATE TABLE `items` (
  `ite_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `itemName` varchar(40) DEFAULT NULL,
  `itemNumber` int(10) unsigned NOT NULL,
  PRIMARY KEY (`ite_id`),
  UNIQUE KEY `itemName` (`itemName`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=latin1


delimiter |

create trigger item_beforeinsert before insert on items
    for each row begin
    if new.itemNumber < 50 then
        set new.ite_id = null;
    end if;
end;
|

now the following command doesn’t cause a trigger

insert items( itemname, itemnumber) values ( 'xyz', 1 );

any help would be very much appreciated, thanks!

Answer 1

Your ite_ID is not null and you want to set it null with your trigger, beside that it’s auto increment, so you wont be able to ‘control’ all the values to assign to that field, I.E it wont overwrite values