Re: Operand should contain 1 column(s) - how to get extra info from subquery?

[Alan Densmore]

Peter thanks so much for the help -
I see how yours is simpler/cleaner, and I didn't know about ifnull() etc. - that seems like it could help, I tweaked it to what I needed to test:

-----------------
select

p.*,
ifnull(t.persontag_enddate,'Unknown') as 'expiry date',
date_format(t.persontag_enddate, '%M %e, %Y') as display_persontag_enddate

from
persons p
left join
persons_tags t using(person_id)

where

p.person_withdrawn != 1
and
(
t.persontag_startdate < now()-interval 3 year
and
t.tag_id = 170
)

order by person_last, person_first;
-----------------

The main thing I know that I need more than the above though, is to ALSO return persons that are *NOT IN* the join table (t) *AT ALL*, while still returning that display_persontag_enddate info for the people who *ARE* in it.

It's that combo I don't know how to achieve and still get the extra "display_persontag_enddate" info when it exists (when they ARE in the join table). Does that make sense?