Re: left outer join to pull in most recent record

select distinct s_regno, max(s_stock_no) over (partition by s_regno 
order by s_regno) from stock;

Am 09.10.2018 um 15:18 schrieb Gary Stainburn:
> I have the following stock list table.
>
> # select * from stock;
>   s_stock_no | s_regno
> ------------+---------
>   N12345     | GPS1
>   N12346     | TEST1
>   U123       | GPS1
> (3 rows)
>
> This shows two vehicles.
> GPS1 was originally a new vehicle which we then sold.
> TEST1 is also a new vehicle
> GPS1 is sunsequently purchased back from the customer as a part exchange, and
> is put on the stock table as a used car.
>
> If I later want to do a search based on the registration number, wishing to
> retrieve the most recent record what is the *best* (quickest or least CPU
> time depending on your preference) way to do this?
>
> By most recent record, I mean the record with the highest stock number.
>
> I'm looking for a solution to do a straight select where.....
> but I am also looking for a solution that can be used in a left join, for
> example
>
> select diary.*, stock.*
> 	from diary
> 	left outer join stock on ...........
>

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