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Re: Where to put the return

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Robert Klemme <shortcutter@googlemail.com> writes:

> 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.

Because I have seen to many cases where coders did something like:
    SELECT *
    FROM   myTable

You could say that when you use all fields that is not a problem, but
even then I would not use it. But others do.

Also if you use the wrong variable in your getQuery the change you get
an error (what you should want) is bigger with a accessing by name as
by index.


>> 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?

See above.


>>> 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.)

I removed the ‘ORDER BY’ in my views. It is handy when using a
database browser, but not that important.

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof

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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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