Re: pivot functions with variable number of columns - Mailing list pgsql-general

From Misa Simic
Subject Re: pivot functions with variable number of columns
Date
Msg-id CAH3i69=4F1Xpv==OROmEHu-VZ4nKuE0tZiZMk=vzNzOrboCg3g@mail.gmail.com
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In response to Re: pivot functions with variable number of columns  (Pavel Stehule <pavel.stehule@gmail.com>)
Responses Re: pivot functions with variable number of columns
List pgsql-general
Hi Pavel,

Hm... To me workaround looks as exactly as the same thing?

1) uses Dynamic SQL to bulid query (but returns refcursor insted of text)

2) client still needs to execute 2 commands (second is fetch instead of execute 'result')

However, based on your name, and the name of the blog author :) I have made conlusion you are working on Stored Procedures things?

I have a few questions about that... But will send another mail to dont mix subjects...

Cheers,

Misa

On Thursday, September 6, 2012, Pavel Stehule wrote:
Hello

2012/9/6 Misa Simic <misa.simic@gmail.com>:
> That is one of most wanted features of PostgreSQL, what is not solved yet,,,
>
> But it seems will be soon with introductions of Stored Procedures...
>

I wish :)

> For now, you must "know" what result (columns) you expects...
>
> So the only one option for now is to use Dynamic SQL - to build your query
> dynamically based on data in your table (based on column what should be
> pivoted)..
>
> And then execute that query...
>
> You can use your client side language to build SQL or inisde DB you could
> make function what returns "text" as your Dynamic SQL and then execute it
> from your client...
>

there is a some workaround

http://okbob.blogspot.cz/2008/08/using-cursors-for-generating-cross.html

Pavel

> Kind Regards,
>
> Misa
>
> 2012/9/6 punnoose <punnoose.pj@dwisesolutions.com>
>>
>> I want to have a pivot like function in which i should have variable
>> number
>> of columns.i went for crosstab but it doesnot support variable number of
>> columns.Can any body suggest an alternative.like if i have a event at a
>> particular time of the day like one at 02:35,11:34, then i should have
>> column name 02:35,11:34.
>> Please do help me.
>> Punnoose
>>
>>
>>
>>
>> --
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>>
>>
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