Re: left outer join only select newest record - Mailing list pgsql-sql

Hello again, Gary,

I don't know if this query works OK, i havent tried it.

But, If I understood correctly this can be one way to do what you want. 
Could you please tell me if it worked and if it didn't why, so we can tweak 
it.

Best,
Oliver

SELECT subq.s_stock_no,subq.s_regno,subq.s_vin,subq.s_created,subq.m, 
sec.s_creacted
FROM
(select s_stock_no, s_regno, s_vin, s_created, MAX(ud_id) as m
from  stock s
left outer join used_diary u
on s.s_regno = u.ud_pex_registrationwhere s_stock_no = 'UL15470';
GROUP s_stock_no,s_regno,s_vin,s_created
) subq
JOIN
used_diary sec
ON subq.m = sec.ud_id

----- Original Message ----- 
From: "Gary Stainburn" <gary.stainburn@ringways.co.uk>
To: <pgsql-sql@postgresql.org>
Sent: Wednesday, May 23, 2012 10:47 AM
Subject: Re: [SQL] left outer join only select newest record


> Appologies for not making it clearer. stock_details is simply a view of 
> table
> stock, pulling in some lookup values.  used_diary is the name of the table
> containing the tax requests. It's called the used_diary because it was the
> diary for taxing used vehicles.
>
> Here is a select to show the problem. There is one stock record and two 
> tax
> records. What I'm looking for is how I can return only the second tax 
> record,
> the one with the highest ud_id
>
> select s_stock_no, s_regno, s_vin, s_created, ud_id, ud_handover_date from
> stock s left outer join used_diary u on s.s_regno = u.ud_pex_registration
> where s_stock_no = 'UL15470';
>
> s_stock_no | s_regno |       s_vin       |         s_created          |
> ud_id | ud_handover_date
> ------------+---------+-------------------+----------------------------+-------+------------------
> UL15470    | YG12*** | KNADN312LC6****** | 2012-05-21 09:15:31.569471 |
> 41892 | 2012-04-06
> UL15470    | YG12*** | KNADN312LC6****** | 2012-05-21 09:15:31.569471 |
> 42363 | 2012-05-16
> (2 rows)
>
>
> On Wednesday 23 May 2012 10:37:31 Oliveiros d'Azevedo Cristina wrote:
>> Gary,
>>
>> You describe two tables vehicle stock and tax requests. The former has a
>> one-to-many relationship wit the second one, right?
>>
>> But your query involves stock details and used_diary.
>>
>> What is the relationship of these two new tables to the previous ones?
>>
>> Could you please kindly supply an example of what you have and of the
>> desired output? For me it would be easier...
>>
>> Best,
>> Oliver
>>
>> ----- Original Message -----
>> From: "Gary Stainburn" <gary.stainburn@ringways.co.uk>
>> To: <pgsql-sql@postgresql.org>
>> Sent: Wednesday, May 23, 2012 10:27 AM
>> Subject: [SQL] left outer join only select newest record
>>
>> > Hi folks,
>> >
>> > I know I've seen posts like this before but Google isn't helping today.
>> >
>> > I have two tables, vehicle stock and tax requests. Each vehicle can be
>> > taxed
>> > more than once, but I only want to pull in the most recent tax 
>> > request -
>> > the
>> > one with the highest ud_id.
>> >
>> > I have the following, which obviously returning multiple records which
>> > then
>> > appears that the same vehicle is in stock multiple times.  How can I 
>> > make
>> > it
>> > so we only show each vehicle once, showing the most recent tax request
>> > details.
>> >
>> >
>> > select * from stock_details s
>> > left outer join used_diary u on s.s_registration = u.ud_registration;
>> >
>> >
>> > --
>> > Gary Stainburn
>> > Group I.T. Manager
>> > Ringways Garages
>> > http://www.ringways.co.uk
>> >
>> > --
>> > Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
>> > To make changes to your subscription:
>> > http://www.postgresql.org/mailpref/pgsql-sql
>
>
>
> -- 
> Gary Stainburn
> Group I.T. Manager
> Ringways Garages
> http://www.ringways.co.uk
>
> -- 
> Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-sql