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Re: Where to put the return

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On 19.08.2017 12:54, Cecil Westerhof wrote:
> Robert Klemme <shortcutter@googlemail.com> writes:
>> On 15.08.2017 08:12, Cecil Westerhof wrote:

>>> One of the things I do is make sure you cannot use index. I find that
>>> a very bad habit.
>>
>> Why?
> 
> I have to often seen that a database definition changed and there was
> a big problem with the code, because a lot of queries had to be
> changed.

What does that have to do with accessing via index or name?  You are 
talking about changing queries because of changed schema.  But that does 
not necessarily have effects on the layout of the ResultSet.

> I agree that with the kind of programs my wrapper will be used it
> probably is mot a big deal, but it does not hurt to make people learn
> to use better practises.

Again, why is it a better practice to avoid accessing columns via index 
instead of name?

>> Sorted view is another thing I would not do.  I am not sure that is even
>> a supported features across most databases.  It does have issues -
>> technical and conceptual.
> 
> In this case it is on a SQLite3 database which does have it and I
> think it very unlikely to change. But you are right: when I want the
> code to be portable I should not use this, or add a comment to the
> code.

It's not only about portability.  It is also about conceptual issues.  A 
view is just a view on data.  In relational theory, which is the 
foundation of RDBMS and SQL, a view is just a special subset of the 
data.  (But do not make the mistake to reduce SQL to relational theory - 
it is actually more.)

Cheers

	robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

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Thread

Where to put the return Cecil Westerhof <Cecil@decebal.nl> - 2017-08-11 10:30 +0200
  Re: Where to put the return Cecil Westerhof <Cecil@decebal.nl> - 2017-08-11 12:24 +0200
  Re: Where to put the return Eric Douglas <e.d.programmer@gmail.com> - 2017-08-11 08:31 -0700
  Re: Where to put the return Arne Vajhøj <arne@vajhoej.dk> - 2017-08-11 20:33 -0400
    Re: Where to put the return Robert Klemme <shortcutter@googlemail.com> - 2017-08-13 00:27 +0200
      Re: Where to put the return Arne Vajhøj <arne@vajhoej.dk> - 2017-08-12 21:41 -0400
        Re: Where to put the return Robert Klemme <shortcutter@googlemail.com> - 2017-08-13 13:15 +0200
      Re: Where to put the return Cecil Westerhof <Cecil@decebal.nl> - 2017-08-15 08:12 +0200
        Re: Where to put the return Robert Klemme <shortcutter@googlemail.com> - 2017-08-19 11:10 +0200
          Re: Where to put the return Cecil Westerhof <Cecil@decebal.nl> - 2017-08-19 12:54 +0200
            Re: Where to put the return Cecil Westerhof <Cecil@decebal.nl> - 2017-08-19 13:46 +0200
              Re: Where to put the return Cecil Westerhof <Cecil@decebal.nl> - 2017-08-19 14:10 +0200
              Re: Where to put the return Robert Klemme <shortcutter@googlemail.com> - 2017-08-19 15:35 +0200
                Re: Where to put the return Arne Vajhøj <arne@vajhoej.dk> - 2017-08-19 09:48 -0400
                Re: Where to put the return Robert Klemme <shortcutter@googlemail.com> - 2017-08-19 23:26 +0200
                Re: Where to put the return Arne Vajhøj <arne@vajhoej.dk> - 2017-08-19 20:01 -0400
                Re: Where to put the return Robert Klemme <shortcutter@googlemail.com> - 2017-08-20 19:30 +0200
                Re: Where to put the return Cecil Westerhof <Cecil@decebal.nl> - 2017-08-19 17:06 +0200
            Re: Where to put the return Robert Klemme <shortcutter@googlemail.com> - 2017-08-19 15:35 +0200
              Re: Where to put the return Arne Vajhøj <arne@vajhoej.dk> - 2017-08-19 09:43 -0400
              Re: Where to put the return Cecil Westerhof <Cecil@decebal.nl> - 2017-08-19 17:15 +0200
                Re: Where to put the return Robert Klemme <shortcutter@googlemail.com> - 2017-08-21 22:33 +0200
          Re: Where to put the return lewbloch@gmail.com - 2017-08-19 09:20 -0700
            Re: Where to put the return Robert Klemme <shortcutter@googlemail.com> - 2017-08-21 22:29 +0200
    Re: Where to put the return Eric Douglas <e.d.programmer@gmail.com> - 2017-08-14 05:11 -0700
  Re: Where to put the return Brixomatic <brixomatic@yahoo.com> - 2017-08-31 19:27 +0200

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