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Thread: Re: [SQL] need some magic with generate_series()

Re: [SQL] need some magic with generate_series()

From
"Alexander Gataric"
Date:
I would create a common table expression with the series from Filip and left join to the table you need to report on.

Sent from my smartphone

----- Reply message -----
From: "Andreas" <maps.on@gmx.net>
To: "Filip Rembiałkowski" <plk.zuber@gmail.com>
Cc: "jan zimmek" <jan.zimmek@web.de>, <pgsql-sql@postgresql.org>
Subject: [SQL] need some magic with generate_series()
Date: Tue, Jan 22, 2013 4:49 pm


Thanks Filip,
with your help I came a step further.   :)

Could I do the folowing without using a function?


CREATE OR REPLACE FUNCTION month_series ( date )
 RETURNS table ( monthnr integer )
AS
$BODY$

   select  to_char ( m, 'YYYYMM' )::integer
   from    generate_series ( $1, current_date, '1 month'::interval )   as  m

$BODY$ LANGUAGE sql STABLE;


select  project_id, month_series ( createdate )
from    projects
order by 1, 2;



Am 22.01.2013 22:52, schrieb Filip Rembiałkowski:
> or even
>
> select m from generate_series( '20121101'::date, '20130101'::date, '1
> month'::interval) m;
>
>
>
> On Tue, Jan 22, 2013 at 3:49 PM, jan zimmek <jan.zimmek@web.de> wrote:
>> hi andreas,
>>
>> this might give you an idea how to generate series of dates (or other datatypes):
>>
>> select g, (current_date + (g||' month')::interval)::date from generate_series(1,12) g;
>>
>> regards
>> jan
>>
>> Am 22.01.2013 um 22:41 schrieb Andreas <maps.on@gmx.net>:
>>
>>> Hi
>>> I need a series of month numbers like  201212, 201301 YYYYMM to join other sources against it.
>>>
>>> I've got a table that describes projects:
>>> projects ( id INT, project TEXT, startdate DATE )
>>>
>>> and some others that log events
>>> events( project_id INT, createdate DATE, ...)
>>>
>>> to show some statistics I have to count events and present it as a view with the project name and the month as YYYYMM starting with startdate of the projects.
>>>
>>> My problem is that there probaply arent any events in a month but I still need this line in the output.
>>> So somehow I need to have a select that generates:
>>>
>>> project 7,201211
>>> project 7,201212
>>> project 7,201301
>>>
>>> It'd be utterly cool to get this for every project in the projects table with one select.
>>>
>>> Is there hope?
>>>
>>>
>>> --
>>> Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
>>> To make changes to your subscription:
>>> http://www.postgresql.org/mailpref/pgsql-sql
>>
>>
>> --
>> Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
>> To make changes to your subscription:
>> http://www.postgresql.org/mailpref/pgsql-sql



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Re: need some magic with generate_series()

From
Andreas
Date:
The query should work for all projects in the projects table where 
everyone has a seperate startdate for the series.
For the join I need ( project_id, month_nr ).

When I tried I couldn't figure out how to feed the startdate into 
Filip's expression without using the function to encapsulate the 
generate_series().
The folowing doesn't work:

select  project_id,          (    select  to_char ( m, 'YYYYMM' )::integer               from    generate_series (
projects.createdate,
 
current_date, '1 month'::interval )   as  m         )
from    projects
order by 1, 2;



Am 23.01.2013 01:08, schrieb Alexander Gataric:
> I would create a common table expression with the series from Filip 
> and left join to the table you need to report on.
>
> ----- Reply message -----
> From: "Andreas" <maps.on@gmx.net>
> To: "Filip Rembiałkowski" <plk.zuber@gmail.com>
> Cc: "jan zimmek" <jan.zimmek@web.de>, <pgsql-sql@postgresql.org>
> Subject: [SQL] need some magic with generate_series()
> Date: Tue, Jan 22, 2013 4:49 pm
>
>
> Thanks Filip,
> with your help I came a step further.   :)
>
> Could I do the folowing without using a function?
>
>
> CREATE OR REPLACE FUNCTION month_series ( date )
>  RETURNS table ( monthnr integer )
> AS
> $BODY$
>
>    select  to_char ( m, 'YYYYMM' )::integer
>    from    generate_series ( $1, current_date, '1 month'::interval )   
> as  m
>
> $BODY$ LANGUAGE sql STABLE;
>
>
> select  project_id, month_series ( createdate )
> from    projects
> order by 1, 2;
>
>
>
> Am 22.01.2013 22:52, schrieb Filip Rembiałkowski:
> > or even
> >
> > select m from generate_series( '20121101'::date, '20130101'::date, '1
> > month'::interval) m;
> >
> >
> >
> > On Tue, Jan 22, 2013 at 3:49 PM, jan zimmek <jan.zimmek@web.de> wrote:
> >> hi andreas,
> >>
> >> this might give you an idea how to generate series of dates (or 
> other datatypes):
> >>
> >> select g, (current_date + (g||' month')::interval)::date from 
> generate_series(1,12) g;
> >>
> >> regards
> >> jan
> >>
> >> Am 22.01.2013 um 22:41 schrieb Andreas <maps.on@gmx.net>:
> >>
> >>> Hi
> >>> I need a series of month numbers like  201212, 201301 YYYYMM to 
> join other sources against it.
> >>>
> >>> I've got a table that describes projects:
> >>> projects ( id INT, project TEXT, startdate DATE )
> >>>
> >>> and some others that log events
> >>> events( project_id INT, createdate DATE, ...)
> >>>
> >>> to show some statistics I have to count events and present it as a 
> view with the project name and the month as YYYYMM starting with 
> startdate of the projects.
> >>>
> >>> My problem is that there probaply arent any events in a month but 
> I still need this line in the output.
> >>> So somehow I need to have a select that generates:
> >>>
> >>> project 7,201211
> >>> project 7,201212
> >>> project 7,201301
> >>>
> >>> It'd be utterly cool to get this for every project in the projects 
> table with one select.
> >>>
> >>> Is there hope?
> >>>
> >>>
> >>> --
> >>> Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
> >>> To make changes to your subscription:
> >>> http://www.postgresql.org/mailpref/pgsql-sql
> >>
> >>
> >> --
> >> Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
> >> To make changes to your subscription:
> >> http://www.postgresql.org/mailpref/pgsql-sql
>
>
>
> -- 
> Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
> To make changes to your subscription:
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Re: Re: [SQL] need some magic with generate_series()

From
Andreas
Date:
I'm sorry to prove that daft.  :(

generate_series needs the startdate of every project to generate the 
specific list of monthnumbers for every project.
To join against this the list needs to have a column with the project_id.

So I get something like this but still I cant reference the columns of 
the projects within the query that generates the series.


with projectstart ( project_id, startdate )
as    (        select  project_id, startdate        from    projects    )

select  project_id, m
from    projectstart    as  p    left join   (                    select  p.project_id, to_char ( m, 'YYYYMM'
)::integer                   from    generate_series ( p.startdate, 
 
current_date, '1 month'::interval ) as m                )       as  x    using ( project_id );




Am 23.01.2013 01:08, schrieb Alexander Gataric:
> I would create a common table expression with the series from Filip 
> and left join to the table you need to report on.
>
> Sent from my smartphone
>
> ----- Reply message -----
> From: "Andreas" <maps.on@gmx.net>
> To: "Filip Rembiałkowski" <plk.zuber@gmail.com>
> Cc: "jan zimmek" <jan.zimmek@web.de>, <pgsql-sql@postgresql.org>
> Subject: [SQL] need some magic with generate_series()
> Date: Tue, Jan 22, 2013 4:49 pm
>
>
> Thanks Filip,
> with your help I came a step further.   :)
>
> Could I do the folowing without using a function?
>
>
> CREATE OR REPLACE FUNCTION month_series ( date )
>  RETURNS table ( monthnr integer )
> AS
> $BODY$
>
>    select  to_char ( m, 'YYYYMM' )::integer
>    from    generate_series ( $1, current_date, '1 month'::interval )   
> as  m
>
> $BODY$ LANGUAGE sql STABLE;
>
>
> select  project_id, month_series ( createdate )
> from    projects
> order by 1, 2;
>
>
>
> Am 22.01.2013 22:52, schrieb Filip Rembiałkowski:
> > or even
> >
> > select m from generate_series( '20121101'::date, '20130101'::date, '1
> > month'::interval) m;
> >
> >
> >
> > On Tue, Jan 22, 2013 at 3:49 PM, jan zimmek <jan.zimmek@web.de> wrote:
> >> hi andreas,
> >>
> >> this might give you an idea how to generate series of dates (or 
> other datatypes):
> >>
> >> select g, (current_date + (g||' month')::interval)::date from 
> generate_series(1,12) g;
> >>
> >> regards
> >> jan
> >>
> >> Am 22.01.2013 um 22:41 schrieb Andreas <maps.on@gmx.net>:
> >>
> >>> Hi
> >>> I need a series of month numbers like  201212, 201301 YYYYMM to 
> join other sources against it.
> >>>
> >>> I've got a table that describes projects:
> >>> projects ( id INT, project TEXT, startdate DATE )
> >>>
> >>> and some others that log events
> >>> events( project_id INT, createdate DATE, ...)
> >>>
> >>> to show some statistics I have to count events and present it as a 
> view with the project name and the month as YYYYMM starting with 
> startdate of the projects.
> >>>
> >>> My problem is that there probaply arent any events in a month but 
> I still need this line in the output.
> >>> So somehow I need to have a select that generates:
> >>>
> >>> project 7,201211
> >>> project 7,201212
> >>> project 7,201301
> >>>
> >>> It'd be utterly cool to get this for every project in the projects 
> table with one select.
> >>>
> >>> Is there hope?
> >>>
> >>>
> >>> --
> >>> Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
> >>> To make changes to your subscription:
> >>> http://www.postgresql.org/mailpref/pgsql-sql
> >>
> >>
> >> --
> >> Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
> >> To make changes to your subscription:
> >> http://www.postgresql.org/mailpref/pgsql-sql
>
>
>
> -- 
> Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-sql