Re: Dynamically update NEW columns in plpgsql trigger

Hey Nick,

You may do it with PL/pgSQL more easily with hstore module.
Please, refer to http://www.postgresql.org/docs/9.0/static/hstore.html
Please, look at the hstore(record) and populate_record(record, hstore)
function. Hope this helps.

And I think it will be more faster then you solution.

Regards,
Dmitriy

2010/9/9 Nick <nboutelier(at)gmail(dot)com>

> I need to dynamically update NEW columns. Ive been inserting the NEW
> values into a temp table, updating them, then passing the temp table
> values back to NEW (is there a better way?). Ive had success with this
> method unless there is a null value...
>
> EXECUTE 'CREATE TEMP TABLE new AS SELECT $1.*' USING NEW;
> EXECUTE 'UPDATE new SET ' || dyn_col_name || ' = 1';
> EXECUTE 'SELECT * FROM new' INTO NEW;
> EXECUTE 'DROP TABLE new';
>
> This last line...
> EXECUTE 'SELECT $1.' || dyn_col_name INTO val USING NEW;
>
> gives the ERROR: could not identify column "col_one" in record data
> type.
>
> However RAISE EXCEPTION '%',NEW.col_one;
> returns "1" correctly.
>
> If col_one does does not start out as a null value, then everything
> works. Why does the passing from temp table back to NEW lose the USING
> functionality?
>
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