auto increment on update?

[Noppy]

is there a way of increasing a number automatically when the field is updated. I want to have a voting form that just adds 1 each time a user submits.

If i output the last number into a hidden field and add 1 it is possible that if someone has the page open for a long time other users could vote and the number stored in their form would be lower than the current number submitted by other users.

any ideas appreciated. oh iam using php and mysql

[tripy]

Use a stored procedure, which will handle the increment or create an trigger that will fire before an insert

http://dev.mysql.com/doc/refman/5.0/en/triggers.html
http://dev.mysql.com/doc/refman/5.0/...-routines.html

[wysiwyg]

How about:
UPDATE votings SET some_count = some_count + 1

[neron-fx]

I like wysiwyg's suggestion

Simple yet effective!

[longneck]

a trigger is overkill. use wysiwyg's method.

[Noppy]

How about:
UPDATE votings SET some_count = some_count + 1

thanks everyone. thats what i was after as presumably it will add 1 to whatever is currently in the table rather than updating a number that has been output and had 1 added.

thanks

[wwb_99]

Really, you should be capturing votes then counting the votes, no incrementing a field, then totaling that. Audit trails are handy . . . .