Re: Subquery to select max(date) value

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От Ken Tanzer
Тема Re: Subquery to select max(date) value
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Msg-id CAD3a31U1_V0z9X22wD=1FQ9iYr+KbY8J3NxQpk0Q5Dq5M151fw@mail.gmail.com
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Ответ на Re: Subquery to select max(date) value  (Rich Shepard <rshepard@appl-ecosys.com>)
Ответы Re: Subquery to select max(date) value  (Rich Shepard <rshepard@appl-ecosys.com>)
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On Tue, Feb 12, 2019 at 2:48 PM Rich Shepard <rshepard@appl-ecosys.com> wrote:
On Tue, 12 Feb 2019, Rich Shepard wrote:

>      A.next_contact = (select (max(A.next_contact)) from Activities as A)

Errata:

The parentheses around the max aggregate are not necessary.

A.next_contact now displays at the end of each returned row as 'infinity'.

Your subquery isn't doing anything to match on person_id, so it's going to match all the records with the highest next_contact in activities.

I think you want something more like:

A.next_contact = (select (max(A.next_contact)) from Activities as A2 WHERE A2.person_id=A.person_id)

Or, for that matter, since next_contact is all that you're drawing from activities, you can also just put it in the select:

select (P.person_id, P.lname, P.fname, P.direct_phone, O.org_name, 
(select max(A.next_contact) from Activities as A WHERE p.person_id=A.person_id)
FROM ...


Cheers,
Ken
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