Re: PL/PgSQL: stmt_fors and variable value after loop

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Marko Tiikkaja <marko(at)joh(dot)to>
Cc: PG Docs <pgsql-docs(at)postgresql(dot)org>
Subject: Re: PL/PgSQL: stmt_fors and variable value after loop
Date: 2015-01-19 16:24:04
Message-ID: 27460.1421684644@sss.pgh.pa.us
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Marko Tiikkaja <marko(at)joh(dot)to> writes:
> On 1/19/15 4:44 PM, Tom Lane wrote:
>> It seems to me that to do so would mostly be to encourage sloppy
>> programming practices, at the price of constraining future implementation
>> changes. Can you give a compelling example of a non-kluge usage for
>> such an assumption?

> What I'm doing would look something like this:
> ...
> Available workarounds right now would be, as far as I can tell:

> 1) Have separate variables which I assign to inside the loop, and use
> those in case the loop found exactly one row
> 2) Aggregate the (currency, balance) pairs into an array first, and
> decide based on the array's cardinality what to do
> 3) Use a count(*) OVER () inside the query and EXIT if that count is 1
> 4) Extract the values back from the sole element in the
> _AvailableAccounts array

> I don't particularly like any of those.

I would have said that (4) would be the natural thing. What have you
got against it?

regards, tom lane

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