At 08:30 PM 12/03/2009, you wrote:

>It is not non-unicode caracters it is characters from win1251 set (latin)

win1251 is not unicode, and a "collation" called UNICODE_FSS is not a valid collation for the win1251 character set.

You will need to create a new (temporary) column and use it to convert your data, viz.

alter table yourtable
add tempunicode varchar(50) character set UNICODE_FSS

Commit that; then do

update yourtable
set tempunicode = cast (ExistingColumn as varchar(50) character set UNICODE_FSS)

Commit that; then check that the new column has the data correctly.

Then drop the ExistingColumn; then do

alter table yourtable
add ExistingColumn varchar(50) character set UNICODE_FSS

Commit that; then do

update yourtable
set ExistingColumn = tempunicode

Check the data; then finally, drop the tempunicode column.

>Here is one add: I was backup and restore my firebrid database 2.0 with firebird 2.1.1 in all cases when this don't work!

Backing up and restoring does not convert single-byte data (e.g. win1251) into unicode, which is multi-byte.

Also consider converting this data to UTF8, rather than UNICODE_FSS, which is very limited in its capability and not very portable.

./hb