Re: A JOIN question

On Mon, Dec 30, 2019 at 02:47:53PM -0700, Michael Lewis wrote:
> >
> > LEFT join mfg_vendor_relationship on
> > mfg_vendor_relationship.mfg_key = mfg_part.mfg_key
> > AND
> > mfg_vendor_relationship.project_key = bom_item.project_key
> > LEFT join vendor on
> > mfg_vendor_relationship.vendor_key = vendor.vendor_key
> >
>
> Perhaps I am missing something, but it seems like just a matter of changing
> inner join to left so you keep what you already have and augment vendor
> information when it exists. I never use right joins (I re-write to always
> declare as left) so I am not sure if the right join near the top screws
> that up. I might consider using a UNION ALL to combine sets where values
> are NULL with left joins, and use plain (inner) joins for the not nulls.

Thanks. That looks like it gives me what I need.

RE right joins, I just got started doing that, and it is easier for me to
think that way.

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