Re: row number with in cursor

On 10/06/2016 06:01 PM, Kevin Duffy wrote:
> The cursor is defined as follows:
>
> currDR CURSOR (r character(15), sD date ) IS
> select rate_key, rate_date, rate_value,
> LAG(rate_date, 1 , null) OVER w as lag_r_date ,
> LAG(rate_value, 1, null) Over w as lag_r_value ,
> ( LAG(rate_value, 1, null) Over w /100 * ( rate_date -
> LAG(rate_date, 1 , null) OVER w ) ) / 360 as overnight_rate_return
> from rate_quote
> where rate_key = r and rate_date >= sD
> WINDOW w as (PARTITION BY rate_key order by rate_date ROWS 1
> PRECEDING )
> order by 2 ;
>
> Cursor works fine
> Could I add a row number to the above?

Heading out the door, but here is something:

https://www.postgresql.org/docs/9.6/static/functions-window.html

and a quick search using 'postgres row number':

https://www.google.com/search?q=postgres+row+number&ie=utf-8&oe=utf-8

>
> KD
>
> On Thu, Oct 6, 2016 at 8:26 PM, Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com
> <mailto:adrian(dot)klaver(at)aklaver(dot)com>> wrote:
>
> On 10/06/2016 05:05 PM, Kevin Duffy wrote:
>
> Hello All:
>
> I need your kind assistance, to learn if it is possible
> within a cursor to know what row you are on.
>
>
> What version of Postgres?
>
> Are you actually using a CURSOR as defined by plpgsql?:
>
> https://www.postgresql.org/docs/9.6/static/plpgsql-cursors.html
> <https://www.postgresql.org/docs/9.6/static/plpgsql-cursors.html>
>
> Looks like you are LOOPing over the results of a function?
>
> Something like this:
>
> for currDateRate IN currDR( rate_in, start_date ) LOOP
>
> raise notice ' currDateRate.rate_date: %',
> currDateRate.rate_date ;
> raise notice ' currDateRate.lag_r_value: %',
> currDateRate.lag_r_value ;
> raise notice ' currDateRate.rate_value: %',
> currDateRate.rate_value ;
> raise notice ' currDateRate.overnight_r: %',
> currDateRate.overnight_rate_return ;
> tr_index := tr_index *( 1+
> currDateRate.overnight_rate_return ) ;
> raise notice ' tr_index: %',tr_index ;
> -- this does NOT work
> raise notice ' row number %', currDateRate%ROWNUMBER ;
>
>
> There is no ROWNUMBER in plpgsql(I am assuming you are using that?).
>
>
> End LOOP;
>
> for testing purposes would like to break out after twenty records.
> Yes I know I could do a simple counter like this:
>
> rtn_cnt := rtn_cnt +1;
> if rtn_cnt >= 20 then
> return rtn_cnt;
> END IF;
>
>
> I think you will need to use some variation of the above.
> Or add an argument to currDR(assuming it is a function) that sets a
> LIMIT.
>
>
>
>
> thamks for your attention to this matter
>
> KD
>
>
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com <mailto:adrian(dot)klaver(at)aklaver(dot)com>
>
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com