xlat expansion of absent VPs

[Phil Mayers]

On 18/06/13 12:08, Arran Cudbard-Bell wrote:
>
> On 18 Jun 2013, at 11:07, Phil Mayers <p.mayers at IMPERIAL.AC.UK> wrote:
>
>> On 06/18/2013 07:27 AM, Brian Candler wrote:
>>
>>> Aside: I think Postgres will reject a quoted string being used in an
>>> integer context.
>>
>> Not correct:
>>
>> db=> create temp table tt (val integer);
>> CREATE TABLE
>> db=> insert into tt values ('1');
>> INSERT 0 1
>
> Will it converted quoted NULLs 'NULL' to actual NULL values? I'm guessing no?

No. That's what NULLIF is for, and it's widely used for that.

TBH we're running into the limitations of using variable interpolation 
for SQL here; the "right" way to do this would be parameter binding and 
passing typed data into the SQL drivers, but that's a lot of work for 
only a very small incremental gain.

It's very, very common in SQL for writers of queries to have to use 
COALESCE, NULLIF, CASE, type coercion and other features to ensure 
proper data values (or for the SQL DB to infer them).

As far as I'm concerned, the *only* thing FreeRADIUS needs to do is 
properly quote the variables it expands into a SQL query, which it 
already does.