Re: BUG #8870: PL/PgSQL, SELECT .. INTO and the number of result columns

2014/1/22 Marko Tiikkaja <marko@joh.to>

> On 1/22/14, 3:48 AM, Tom Lane wrote:
>
>  Marko Tiikkaja <marko@joh.to> writes:
>>
>>>     SELECT * INTO f1, f2 FROM lotsofcolumns;
>>>
>>
>>  I can't say I think this is a good idea, but not sure breaking this case
>>> is worth it either.
>>>
>>
>> Um, I thought the whole point was to complain about that.  If this isn't a
>> mistake, how can you consistently maintain the other one is?
>>
>
> I'm sure you can see a difference between explicitly listing the wrong
> number of columns and using * to ignore trailing columns.  That said, this
> *should* be an error according to the documentation, so it's probably not
> the end of the world if we break it.
>
>
>  In bug #8893 there was some discussion which I interpreted to mean that
>>> we could improve this a bit by checking the number of returned columns
>>> during compile time if there's no * in the target list.  Attached is a
>>> crude patch attempting to do that, which appears to be working.  Any
>>> thoughts?
>>>
>>
>> Ick.  I thought you wanted to do this at first execution, anyway, not in
>> pl_gram.y.
>>
>
> Catching these errors at compile time would be ideal.  If we also want to
> catch the * cases we could also check the result structure before the first
> execution.
>

It is exactly it what is done by plpgsql_check_function - without
introduction new dependencies and without possible performance impacts.

Regards

Pavel




>
>
> Regards,
> Marko Tiikkaja
>
>
>
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