Re: Database ORM query Help

Please post the code of Model and explain what do you want as Queryset?

On Fri, 25 Oct 2019 at 17:26, Cheda me <dvdcedar@gmail.com> wrote:

Hey guys,

I have worked out the SQL query I would like to implement but am currently struggling to create the Django query. I have been attempting to use the .aggregate() & Max() methods but cant seem to get the right result. Any help is much appropriated.

SELECT temp.*
FROM item_detail temp
INNER JOIN
    (SELECT item, MAX(created_date) AS MaxDateTime, MAX(id) AS MaxID
    FROM item_detail
    WHERE approved = true
    GROUP BY item) grouped_join
ON temp.item = grouped_join.item
AND temp.created_date = grouped_join.MaxDateTime
AND temp.id = grouped_join.MaxID

CREATE TABLE item_detail
(
    id INT,
    item INT,
    created_date TIMESTAMP,
    description VARCHAR(10),
    approved BOOLEAN
   
);

INSERT INTO item_detail VALUES(1, 1, '2009-04-03', 'dk', true);
INSERT INTO item_detail VALUES(2, 1, '2009-04-03', 'dk mama', false);
INSERT INTO item_detail VALUES(3, 1, '2009-03-04', 'dk 2', true);
INSERT INTO item_detail VALUES(4, 2, '2009-03-04', 'botw', true);
INSERT INTO item_detail VALUES(5, 2, '2009-04-04', 'botw 2', true);
INSERT INTO item_detail VALUES(6, 3, '2009-03-05', 'cod mw', true);
INSERT INTO item_detail VALUES(7, 4, '2008-12-25', 'bf 4', true);
INSERT INTO item_detail VALUES(8, 4, '2009-01-05', 'bf mw', false);
INSERT INTO item_detail VALUES(9, 2, '2009-04-06', 'botw 4', false);
INSERT INTO item_detail VALUES(10, 3, '2009-04-06', 'cod newy', false);
INSERT INTO item_detail VALUES(12, 1, '2009-04-07', 'dk ea', false);
INSERT INTO item_detail VALUES(13, 1, '2009-05-08', 'dk 3', true);
INSERT INTO item_detail VALUES(14, 1, '2009-05-08', 'dk 3-3', true);

Here is the link to the SQL Fiffle: http://www.sqlfiddle.com/#!17/260b62/1

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