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help / color / mirror / Atom feedFrom: v_kalees <v_kalees@yahoo.com>
To: vyegorov@gmail.com
To: jj08@drivehq.com
Cc: pgsql-sql@lists.postgresql.org
Subject: Re: RE:Re: RE:Re: A complex SQL query
Date: Sun, 8 Sep 2019 03:20:36 +0000 (UTC)
Message-ID: <1458680600.3892087.1567912836455@mail.yahoo.com> (raw)
In-Reply-To: <2261310231000000009736706@www>
References: <2261310231000000009736706@www>
This is much cleaner way
select * from (
select usr_id,
employer,
start_date,
end_date,
rank() OVER (PARTITION BY employer ORDER BY start_date DESC) AS rnk
from <tablename> ) t
where t.rnk=1;
Thanks
On Sunday, September 8, 2019, 7:40:05 AM GMT+5:30, jj08 <jj08@drivehq.com> wrote:
Hello Vicor!
It works!!!
Thank you very much.
--From: vyegorov@gmail.com
--To: jj08@drivehq.com
--CC: pgsql-sql@lists.postgresql.org
--Date: 9/7/2019 2:33:40 PM
--Subject: Re: RE:Re: A complex SQL query
сб, 7 сент. 2019 г. в 21:23, jj08 <jj08@drivehq.com>:
To Janis or other members of the forum:
My sample table contains other columns as well.
One of the columns that I did not include in my first message is "position".
The last table has been modified as follows:
+--------+----------+------------+------------------------+
| usr_id | employer | position + start_date | end_date |
+--------+----------+------------+------------------------+
| A | Goo | CTO | | 201904 |
| A | Micro | Mgr | 201704 | 201903 |
| B | Micro | Engg_Mgr | 201706 | - |
| B | Goo | Researcher | 201012 | 201705 |
| B | Micro | Postdoc | 201001 | 201011 |
+--------+----------+------------+------------------------+
SELECT DISTINCT ON (usr_id)
*
FROM employment
WHERE employer='Micro'
ORDER BY usr_id, start_date DESC; --
Victor Yegorov
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To: pgsql-sql@postgresql.org
Cc: v_kalees@yahoo.com, vyegorov@gmail.com, jj08@drivehq.com, pgsql-sql@lists.postgresql.org
Subject: Re: RE:Re: RE:Re: A complex SQL query
In-Reply-To: <1458680600.3892087.1567912836455@mail.yahoo.com>
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