Re: Problems with using function input paramaters

On Sat, Aug 31, 2019 at 10:05:10AM -0400, stan wrote:
> I have been chasing a bug for a bit now. I even wound up completely rewriting the
> function, which in the end turns out to be a good thing, as it is much cleaner and
> easy to read.
>
> I now believe that the bug is in how I am using an input parameter to the
> function. Here is the function deceleration:
>
> CREATE FUNCTION
> return_previous_month_start_and_end(
> integer)
> RETURNS interval_dates AS $$
>
> Here is one of the places I am using it:
>
>
> my_year := ( select
> cast(extract(year from
> cast(date_trunc('month',
> CURRENT_DATE) - interval ' $1
> month - 1 ' day as date)
> ) as integer)
> ) ;
> This prints the correct value BTW:
>
> RAISE notice 'Called with %', $1 ;
>
> Nay thoughts as to what I am doing wrong?
>
BTW, this article
https://dba.stackexchange.com/questions/159424/how-to-use-function-parameters-in-dynamic-sql-with-execute
seems to imply that I can use the $1 syntax in a string, but others refer to using
the COALESCE functionality, but I am uncertain exactly how to use this here.

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