Re: cast record to array in plpgsql

2009/11/17 Kurt <wazkelzu(at)gmx(dot)net>:
> dear list,
>
> i'm trying to implement a general logging scheme with a plpgsql-trigger.
> The idea is, that after an update the trigger compares the elements of
> OLD and NEW and logs the changes made to the record columns. the trigger
> should be usable by any table, so the field names are not known
> beforehand. the natural solution seems to me to convert the records OLD,
> NEW into 2-dimensional arrays where the second dimension is used to
> address column-name and column_data and to step thru this array.
> e.g. NEW{id=55;name='test'} would become a_new[1][1]='id;
> a_new[1][2]=55; a_new[2][1]='name']; a_new[2][2] = 'test'.
> as i think, that this should be quite a common problem, i would like to
> ask whether some C-guru has already written a CAST-function for RECORD
> to ARRAY, or has some better idea to solve this task.
> thanks in advance, wz

hello

look on hstore contrib module to CVS HEAD

http://okbob.blogspot.com/2009/10/dynamic-access-to-record-fields-in.html

It is for PostgreSQL 8.5, but I believe so code is portable to older versions.

Regards
Pavel Stehule
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