Remove CHARACTER SET UNICODE_FSS from a column in a firebird database

Question

I have a Firebird database with several tables in it. There are several columns who were added when database was created as

alter table Machines add MachineVersion varchar(100) CHARACTER SET UNICODE_FSS

I want to modify these columns to drop the CHARACTER SET UNICODE_FSS so I ran the command

alter table Machines alter column MachineVersion type VARCHAR(100)

Still, when I open the database in SQL Manager the character set for these columns is still UNICODE_FSS.

Is there another syntax for the second command to remove the CHARACTER SET UNICODE_FSS?

Answer 1

alter table Machines alter column MachineVersion type VARCHAR(100)

This query won't change the character set.

If you want to remove charater set you should alter domain like:

update RDB$FIELDS set
RDB$CHARACTER_SET_ID = NULL
where RDB$FIELD_NAME = 'RDB$141'

Instead of RDB$141 use column domain

Answer 2

It is possible to add new column , copy data from old column to new and later to drop old column?