Re: [boost] Boost.SQL, SOCI and beyond

From: Mateusz Loskot (mateusz_at_[hidden])
Date: 2006-10-05 21:53:07

Phil Nash wrote:
> On 10/5/06, Mateusz Loskot <mateusz_at_[hidden]> wrote:
>> Phil Nash wrote:
>>>>>> Row r;
>>>>>> sql << "select * from ex2", into(r);
>>>>>>
>>>>>>>              // Columns may be accessed by position...
>>>>>>>              std::cout << r[0].as<long>() << "\t ";
>>>>>> SOCI equivalent: r.get<long>(0)
>>>>> I consider this a small abstraction mismatch: you apply the index to the row and
>>>>> then you convert the field value to a C++ type. By the way, in this case
>>>>> operator[] is the natural way to express indexing, so I believe that operator
>>>>> overloading should be preferred.
>>>>
>>>> I agree, only and only if elements of a sequence can be
>>>> identified only by index.
>>>> In SOCI, when working with Row representation the situation is
>>>> different - elements of Row can accessed *also* via name,
>>>> what's natural in DBMS, where columns are named.
>>>> So, SOCI interface is consistent and intuitive in this case:
>>>>
>>>> r.get<long>(0)
>>>> r.get<long>("column1)
>>>
>>> What about:
>>>
>>> r[0].as<long>()
>>> r["column1"].as<long>()
>> It's a kind of syntactic sugar and IMHO does not make it more (or less)
>> natural what Nicola is questioning.
> 
> Well, admittedly it's not quite "as the ints do", but it is consistent
> with other languages and libraries (including MS's ADO), and is
> "natural" in the index case.

Yes, I agree.

> I'm not personally too worried which of these is adopted anyway, was
> just pointing out the obvious :-)

Yes, I understand.

> I'm more interested in how the iterator interface works out.

We've started implementing it already.
Do you'd have any imagination how it should work, a few points?

Cheers
-- 
Mateusz Loskot
http://mateusz.loskot.net