Re: Partial update on an postgres upsert violates constraint

Is there any way to check whether the row already exists before checking
constraints ? I still want it to fail if it turns out to be a new row
(which would violate the not null constraint), but updates the row if it
already exists.

Since if that is not possible, I would need to do a query to determine
whether the row exists in the database which kinda eliminates the use of
upsert. (in this case, partial upsert).

On Sun, Nov 20, 2016 at 3:57 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com> writes:
> > ... So looks like constraints are checked before you get to the ON
> CONFLICT section.
>
> Right. ON CONFLICT is a means for dealing with duplicate-key errors in
> the specified (or inferred) unique index. It is *not* an all-purpose
> error catcher. In the case at hand, the given INSERT request fails due
> to not-null constraints that are unrelated to what the ON CONFLICT clause
> tests for.
>
> regards, tom lane
>