Migration FB3- > FB5: NCHAR instead of VCHAR ?

[Nikolaus Kern]

Hello,

I have migrated some databases from Firebird 3x to 5. using a backup and restore cycle.

Now I have recognized that all VCHAR() fields have been migrated to NCHAR VARYING().

The databases have the charset ISO8859_1. I would like to move to UTF-8 but don´t like the effort...

1. Is this change a problem?

2. Do I need to take a different behaviour under consideration?

3. Is there an easy way to move to UTF-8?

Thanks

Niko

[Dimitry Sibiryakov]

Nikolaus Kern wrote 23.05.2025 9:31:
> Now I have recognized that all VCHAR() fields have been migrated to NCHAR VARYING().
>
> The databases have the charset ISO8859_1.

And this is exactly definition of NCHAR in Firebird: string fields having
character set ISO 8859-1.

--
WBR, SD.

[Nikolaus Kern]

Hello,

this statement in the document sounds for me that NCHAR has also the character of CHAR: "NCHAR is a fixed-length character data type with the ISO8859_1 character set. In all other respects it is
the same as CHAR."

CHAR does pad blankes by the end of the string, while VCHAR does not do this.

Niko

[Dimitry Sibiryakov]

Nikolaus Kern wrote 23.05.2025 11:23:
> this statement in the document sounds for me that NCHAR has also the character
> of CHAR: "NCHAR is a fixed-length character data type with the ISO8859_1
> character set. In all other respects it is
> the same as CHAR."

Yes, but "NCHAR" and "NCHAR VARYING" are two different types.

--
WBR, SD.

[Mark Rotteveel]

There is no such thing as VCHAR, there is VARCHAR a.k.a. CHARACTER
VARYING. Firebird doesn't really have NCHAR/NCHAR VARYING, that is just
an alias for CHAR/VARCHAR CHARACTER SET ISO8859_1.

It looks like you're using a tool that displaying NCHAR VARYING if the
columns is VARCHAR CHARACTER SET ISO8859_1.

Mark
--
Mark Rotteveel