>
>
> I read it that he has multiple sales from the same person? In which case
> pretending that the two sales were from different people isn't the correct
> result at all.
Actually it turns out that both cases exist.
>
> I may be missing the point of the query, but wasn't it to add an entry for
> each email address and (if it already exists in people) to update the
> firstname field to match the firstname in the order?
Yes. Basically the sales table is denormalized and I need to create or
update normalized tables from it. As you have pointed out the
difficult scenario is when the same person has multiple sales.
> Given that the results will be returned in random order I would just change
> the "nd" query to SELECT DISTINCT ON (email) , but like I said I may be
> missing the point.
I think in this case I am probably going to have go through the
records one at a time. I run into the same issues with other columns
such as products.
