I need a trigger to prevent duplicate rows.

I want to add a trigger named t1 to the products table.The trigger is activated by the Before Insert event.

Any ideas..

as ever the manuel is your friend

what have you tries so far, where are the problems arising

What's wrong with a unique or primary key constraint?

it's a homework assignment, that's what's wrong with it

This looks like a trick question to me then; the answer the marker is looking for is "do not use a trigger, declare an appropriate constraint instead"

how would a constraint work in MySQL?

I assume like this:
http://www.java2s.com/Tutorial/MySQL...blecommand.htm

Or this:
http://www.java2s.com/Code/SQL/Selec...Constraint.htm

AFAIK you can declare as many constraints as you wish.. the problem is that they are not actually implemented. they are there for compatability reasons but dont' actually do anything as yet. that as certainly the case in May 2007

That is for CHECK constraints, which are something different.

UNIQUE constraints work perfectly well in MySQL

you guys should stop reading the doom 'n gloom naysayers and actually put yer hands on this little beauty

Is that supposed to be an inuendo?

if you can't come in through your front door, try in yer window