To set the charset in Firebird must be in the database creation
CREATE DATABASE <database>
USER <username>
PASSWORD <password>
PAGE_SIZE <pagesize>
DEFAULT CHARACTER SET <charset>
See an example below:
CREATE DATABASE localhost:meter
USER SYSDBA
PASSWORD masterkey
PAGE_SIZE 4096
DEFAULT CHARACTER SET UTF8;
To change an existing charset
ALTER CHARACTER SET charset SET DEFAULT COLLATION collation
Take the example:
alter character set utf8 set default collation unicode_ci_ai
If you use SET DEFAULT COLLATION
on the default character set of the database, you have effectively defined the default grouping for the database.
If you use SET DEFAULT COLLATION
in the connection character set, the string constants will be interpreted according to the new standard grouping. In most situations, this will make no difference, but comparisons may have another result if the grouping changes.