Wow! Monty, again and again I'm quite impressed how fast you're
answering ... I think the great support by you and the mailing list
is a very big advantage of MySQL that most other products are lacking.
On Mo, 1999-03-15 20:46:33 +0200, Michael Widenius wrote:
> Martin> So if sorting treats 'a' and 'ä' (a umlaut) as the same,
> Martin> then also 'Bar' and 'Bär' are seen as duplicates.
>
> The above isn't completely true: 'Bar' and 'Bär' are treated as
> distinct values , while 'BAR' and 'bar' isn't distinct
Sorry, this was written with configure option '--with-charset=german1'
in mind (which is how I compiled our MySQL server), I should have
noted this (or put more emphasis on the _if_ :-).
> In MySQL 3.23 you will be able to do:
>
> SELECT DISTINCT BINARY text_column FROM TABLE;
>
> (The BINARY attribute casts the text_column to a binary column, that
> is sorted / compared according to the ASCII values for the individual
> characters)
Very good, that helps a lot to deal more comfortable with the
"unwanted duplicates" problem!
> Martin> I'm not quite sure, if this behaviour is a bug or an intended (but --
> Martin> in my opinion -- mis-designed) feature.
[...]
> I appreciate any ideas how to do it better. The problem is to make
> everything 'hold' together. I think that the DISTINCT should compare
> the strings the same way as the normal compare operations, and this
> put some restrictions how things can be solved.
Maybe it's overkill for the typical applications MySQL is used for,
but you could take the SQL3 standard as a guideline, which defines
collating sequences and their usage (BTW, my source of information is
<URL: http://ftp.digital.com/pub/standards/sql/ >).
But for the time being I think it's great, if one just can add the
keyword "BINARY" to an expression to make it use the "binary"
ordering.
What then still misses is a way to put binary columns into the current
sorting order mode, e.g. new keywords "NATIONAL CHARACTER" or so.
Regards,
Martin
--
Martin Ramsch <m.ramsch@stripped> <URL: http://home.pages.de/~ramsch/ >
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