Subject Re: [firebird-support] Firebird client connection charset, server charsets and encoding
Author Kjell Rilbe
Milan Babuskov wrote:

> Martijn Tonies wrote:
> > Does anyone know a white-paper or decent explanation of
> > how the client side connection character set, server side char set
> > work together?
> >
> > Is there any encoding done by Firebird?
> Hi Martijn,
> Not a white paper, but maybe this can help.
> You have multiple character sets involved:
> 1. charset of the operating system desktop environment
> 2. connection charset
> 3. character set of a database table column
> There is also a database default charset which is only used as default
> when creating new columns and is completely irrelevant here.
> When you connect it Firebird assumes that all data you send and receive
> is encoded with (2), so if you system charset(1) is different, you need
> to transliterate back and forth in your application code (or database
> access library).
> Once data gets to Firebird, it transliterates between (2) and (3), and
> also back when you read the data.
> Now, if you use NONE, then it means there is no transliteration. If both
> your columns(3) and database connection charset(2) are NONE, there would
> be no transliteration, and you can read and write everything using (1).
> We call this 'garbage in - garbage out' :) There are two problems
> with this:
> 1. Different client applications might use a different operating systems
> Consider english, russian and chinese version of Windows XP working on
> the same database, or even add a few Linux clients that default to UTF8.
> You'll get a mess
> 2. Sorting and various character-based functions like CHAR_LENGTH don't
> not work unless you use ASCII all the time.

Nice summary! Could you please add a few words regarding metadata? What
charset is metadata stored in, and when/where/how does FB transliterate

Kjell Rilbe
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