Re: SQL Subquery on Max(date)

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On Sun, 22 Apr 2007 16:00:08 +0200, Bob Hairgrove <invalid@xxxxxxxxxxx> wrote:

CREATE TABLE oncd_activity_company (
company_id LONG NOT NULL,
activity_id LONG NOT NULL,
due_date DATETIME NOT NULL,
CONSTRAINT pk_oncd_activity_company
PRIMARY KEY (company_id, activity_id),
CONSTRAINT fk_company
FOREIGN KEY (company_id)
REFERENCES oncd_company (company_id),
CONSTRAINT fk_activity
FOREIGN KEY (activity_id)
REFERENCES oncd_activity (activity_id)
);

Actually, all three columns should go into the composite primary key here:
...
CONSTRAINT pk_oncd_activity_company
PRIMARY KEY (company_id, activity_id, due_date),
...
etc. Otherwise, it doesn't make sense to do the GROUP BY on company_id and
activity_id.

--
Bob Hairgrove
NoSpamPlease@xxxxxxxx
.

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