Re: help needed on SPI_modifytuple.

thanks a lot Michael, you've just hit the problem!
Now everything works fine!

Thanks again
Fabrizio

On 9/12/05, Michael Fuhr <mike@fuhr.org> wrote:
> On Mon, Sep 12, 2005 at 04:17:33PM +0200, fabrizio picca wrote:
> > I'm trying to sipmply modify a tuple before it will be inserted in the db.
> > The problem is that when it try to insert the modified tuple with
> > SPI_modifytuple all i get is a SPI_ERROR_ARGUMENT negative (-6) .
> > Could someone help me? i'm reallygoing crazy.
> >
> > What i did is just a fire-before C trigger that acts like this:
>
> Is the trigger fired on INSERT, UPDATE, or both?
>
> >         oldtuple =  trigdata->tg_trigtuple;
> >       newtuple = trigdata->tg_newtuple;
> [...]
> >         rettuple=SPI_modifytuple(rel,newtuple,1,&attnum,&new_value,&isnull);
>
> I didn't look closely at the rest of the code, but if the trigger
> is fired on INSERT then you should pass oldtuple; newtuple will be
> NULL, causing SPI_modifytuple() to fail with SPI_ERROR_ARGUMENT.
> Here's an extract from "Writing Trigger Functions in C" in the
> "Triggers" chapter of the documentation:
>
> tg_trigtuple
>
>   A pointer to the row for which the trigger was fired.  This is
>   the row being inserted, updated, or deleted.  If this trigger was
>   fired for an INSERT or DELETE then this is what you should return
>   from the function if you don't want to replace the row with a
>   different one (in the case of INSERT) or skip the operation.
>
> tg_newtuple
>
>   A pointer to the new version of the row, if the trigger was fired
>   for an UPDATE, and NULL if it is for an INSERT or a DELETE.  This
>   is what you have to return from the function if the event is an
>   UPDATE and you don't want to replace this row by a different one
>   or skip the operation.
>
> --
> Michael Fuhr
>


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