Re: Passing dynamic parameters to a table-returning function

This should be the example used in the docs for LATERAL JOIN rather than
the contrived, rather useless example that is there today.

Moshe Jacobson
Manager of Systems Engineering, Nead Werx Inc. <http://www.neadwerx.com>
2323 Cumberland Parkway · Suite 201 · Atlanta, GA 30339

"Quality is not an act, it is a habit." -- Aristotle

On Mon, Feb 4, 2013 at 6:49 PM, David Johnston <polobo(at)yahoo(dot)com> wrote:

> Moshe Jacobson wrote
> > I'm
> > unsure of the syntax for passing in values from columns in the database
> as
> > the parameters of a set-returning function from which I want to select *.
>
> General form for this in version <= 9.2:
>
> WITH func_call_cte AS (
> SELECT func_call(col1, col2, col3) AS func_result
> FROM table_with_cols_123
> )
> SELECT (func_result).*
> FROM func_call_cte;
>
> 9.3 will have "LATERAL" and so should be much cleaner.
>
> The general idea is you have to put the function into the select-list so it
> can see the columns of the table in the FROM. To avoid multiple
> evaluations
> of the function you have to treat the output set as a single typed column
> (func_result) and then in an outer query layer (in this case outside the
> WITH) you can generically expand the typed column into its component parts.
>
> HTH,
>
> David J.
>
>
>
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